Like Tim said, changing the following changes to info.plist launches the all-in-one:
461 to: <string>Squeak 4.5, VM 4.2.3b1u</string>
463 to: <string>4.5</string>
467 to: <string>org.squeak.SqueakAllInOne45</string>
471 to: <string>Squeak 4.5</string>
515 to: <string>Squeak4.5-13680.image</string>
/Applications/Smalltalk/Build/OneClicks/Squeak-4.5-All-in-One.app/Contents/MacOS/Squeak VM Opt
Squeak3.8.1 of '28 Aug 2006' [latest update: #6747] 4.5
Mac Carbon 4.2.4b1 28-Mar-10 >45CAAEAC-5A1E-4327-9702-7973E3473FDE<