diff --git a/src/NewTools-ChangeSorter/ChangeSorterModel.class.st b/src/NewTools-ChangeSorter/ChangeSorterModel.class.st
index ed27935a5..e2da804f9 100644
--- a/src/NewTools-ChangeSorter/ChangeSorterModel.class.st
+++ b/src/NewTools-ChangeSorter/ChangeSorterModel.class.st
@@ -3,7 +3,7 @@ A ChangeSorterModel is a model used by Change Sorter UIs for computation
 "
 Class {
 	#name : #ChangeSorterModel,
-	#superclass : #AbstractTool,
+	#superclass : #Model,
 	#classVars : [
 		'ClassDescriptionsMap'
 	],
@@ -50,6 +50,17 @@ ChangeSorterModel >> allChanges [
 	^ ChangeSet allChangeSets reverse
 ]
 
+{ #category : #method }
+ChangeSorterModel >> browseVersionsFrom: aMethod [
+	"Create and schedule a Versions Browser, showing all versions of the
+	currently selected message. Answer the browser or nil."
+
+	aMethod selector
+		ifNil: [ self inform: 'Sorry, only actual methods have retrievable versions.'. ^nil ]
+		ifNotNil: [:selector |
+			Smalltalk tools versionBrowser browseVersionsForMethod: aMethod ]
+]
+
 { #category : #text }
 ChangeSorterModel >> buildChangeSetDescriptionFor: changeSet [
 		
diff --git a/src/NewTools-ChangeSorter/SpChangeSorterPresenter.class.st b/src/NewTools-ChangeSorter/SpChangeSorterPresenter.class.st
index 253d11929..ce7fc9bd9 100644
--- a/src/NewTools-ChangeSorter/SpChangeSorterPresenter.class.st
+++ b/src/NewTools-ChangeSorter/SpChangeSorterPresenter.class.st
@@ -65,8 +65,7 @@ SpChangeSorterPresenter >> browseChangeSet [
 
 { #category : #'menu - message' }
 SpChangeSorterPresenter >> browseImplementorsOfMessages [
-
-	self model browseMessagesFrom: self selectedSelector
+	SystemNavigation new browseAllImplementorsOf: self selectedSelector
 ]
 
 { #category : #'menu - message' }
@@ -80,7 +79,7 @@ SpChangeSorterPresenter >> browseMethodFull [
 { #category : #'menu - message' }
 SpChangeSorterPresenter >> browseSendersOfMessages [
 
-	self model browseSendersOfMessagesFrom: self selectedSelector
+	self systemNavigation browseAllSendersOf: self selectedSelector
 ]
 
 { #category : #'menu - message' }
@@ -616,7 +615,7 @@ SpChangeSorterPresenter >> remove [
 SpChangeSorterPresenter >> removeClass [
 	"Remove the selected class from the system, at interactive user request.  Make certain the user really wants to do this, since it is not reversible.  Answer true if removal actually happened."
 
-	(self model removeClass: self selectedClass)
+	(SystemNavigation new removeClass: self selectedClass)
 		ifTrue: [ self setSelectedChangeSet: self selectedChangeSet ]
 ]
 
@@ -631,7 +630,7 @@ SpChangeSorterPresenter >> removeMessage [
 			class := self selectedClass.
 				(class includesSelector: selector) ifFalse:[^ self].
 				method := class>>selector.
-				(self model removeMethod: method inClass: class)
+				(SystemNavigation new removeMethod: method inClass: class)
 					ifTrue: [ self updateMessagesList ]]
 ]
 
diff --git a/src/NewTools-Debugger/StDebugger.class.st b/src/NewTools-Debugger/StDebugger.class.st
index 75cd670b5..ae9b681f6 100644
--- a/src/NewTools-Debugger/StDebugger.class.st
+++ b/src/NewTools-Debugger/StDebugger.class.st
@@ -919,6 +919,23 @@ StDebugger >> proceedDebugSession [
 	self close
 ]
 
+{ #category : #private }
+StDebugger >> protocolSuggestionsFor: aClass [
+
+	| classProtocols reject allExistingProtocols interestingProtocols |
+	classProtocols := aClass organization protocolNames.
+	reject := Set with: Protocol unclassified.
+	allExistingProtocols := (SystemNavigation default
+		                         allExistingProtocolsFor: aClass isMeta not)
+		                        reject: [ :p | classProtocols includes: p ].
+	interestingProtocols := classProtocols
+	                        ,
+		                        (allExistingProtocols asOrderedCollection
+			                         sort: [ :a :b |
+			                         a asLowercase < b asLowercase ]).
+	^ interestingProtocols reject: [ :e | reject includes: e ]
+]
+
 { #category : #actions }
 StDebugger >> recompileMethodTo: aString inContext: aContext notifying: aNotifyer [
 
@@ -995,7 +1012,7 @@ StDebugger >> requestProtocolIn: aClass [
 
 	| entryCompletion applicants choice |
 	self class fastTDD ifTrue: [ ^ Protocol unclassified ].
-	applicants := AbstractTool protocolSuggestionsFor: aClass.
+	applicants := self protocolSuggestionsFor: aClass.
 	entryCompletion := EntryCompletion new
 		                   dataSourceBlock: [ :currText | applicants ];
 		                   filterBlock: [ :currApplicant :currText | 
diff --git a/src/NewTools-Debugger/StDebuggerContextInteractionModel.class.st b/src/NewTools-Debugger/StDebuggerContextInteractionModel.class.st
index 74ae18a6b..3ee2e1685 100644
--- a/src/NewTools-Debugger/StDebuggerContextInteractionModel.class.st
+++ b/src/NewTools-Debugger/StDebuggerContextInteractionModel.class.st
@@ -69,8 +69,7 @@ StDebuggerContextInteractionModel >> doItReceiver [
 
 { #category : #testing }
 StDebuggerContextInteractionModel >> hasBindingInContextOf: aString [
-	"we lookup the name without creating a new variable"
-	^ (context lookupVar: aString declare: false) notNil
+	^ (context lookupVar: aString) notNil
 ]
 
 { #category : #testing }
diff --git a/src/NewTools-MethodBrowsers/MessageBrowser.class.st b/src/NewTools-MethodBrowsers/MessageBrowser.class.st
index e61c170c1..f09d0db92 100644
--- a/src/NewTools-MethodBrowsers/MessageBrowser.class.st
+++ b/src/NewTools-MethodBrowsers/MessageBrowser.class.st
@@ -4,7 +4,7 @@ A MessageBrowser is a UI to browse a list of method, regardless of what they cou
 example: 
 
 MessageBrowser new
-	openWithSpec;
+	open;
 	messages: (SystemNavigation new allSendersOf: #at:)
 	yourself
 "
diff --git a/src/NewTools-MethodBrowsers/MessageList.class.st b/src/NewTools-MethodBrowsers/MessageList.class.st
index 359a41523..1a6ced146 100644
--- a/src/NewTools-MethodBrowsers/MessageList.class.st
+++ b/src/NewTools-MethodBrowsers/MessageList.class.st
@@ -20,7 +20,6 @@ Class {
 	#instVars : [
 		'cachedHierarchy',
 		'topologySort',
-		'model',
 		'method',
 		'listPresenter'
 	],
@@ -44,8 +43,9 @@ MessageList >> browseClassRefs [
 
 { #category : #actions }
 MessageList >> browseMessages [
+
 	self currentMethod ifNotNil: [ :aMethod |
-		 model browseMessagesFrom: aMethod selector ]
+		SystemNavigation new browseImplementorsOf: aMethod selector ]
 ]
 
 { #category : #actions }
@@ -167,9 +167,9 @@ MessageList >> ensureKeyBindingsFor: aWidget [
 
 { #category : #initialization }
 MessageList >> initialize [
-	topologySort := true.
-	model := AbstractTool new.
-	super initialize
+	super initialize.
+	topologySort := true
+
 ]
 
 { #category : #initialization }
@@ -267,11 +267,6 @@ MessageList >> methodClassNameForItem: anItem [
 	^ anItem methodClass ifNotNil: [ :class | class name ] ifNil: [ '' ]
 ]
 
-{ #category : #accessing }
-MessageList >> model [ 
-	^model
-]
-
 { #category : #accessing }
 MessageList >> numberOfElements [
 	^ listPresenter listSize
@@ -312,7 +307,7 @@ MessageList >> protocolNameForItem: anItem [
 MessageList >> removeMethods [
 
 	self currentMethod ifNotNil: [ :aMethod |
-		model removeMethod: aMethod inClass: aMethod methodClass ]
+		SystemNavigation new removeMethod: aMethod inClass: aMethod methodClass ]
 ]
 
 { #category : #selecting }