It would be nice to do more things the Apple way, including porting to modern runtime feature availability check cascades of the Cocoa APIs and using the Apple provided system Frameworks. This seems like a rather major workload and should be targeting 3.8.
Yeah — too much to do for 3.7 at this stage. But what about dropping 32 bit and maybe bumping the OS up? Maybe 10.11 is too new, but something newer than 10.6? Or maybe 10.11 is a good target — looks like it’s been around 2+ years, and Apple now provides free updates. -CHB