Is it possible to locate previous versions of a font design?
What exactly do you mean? Are you trying to go back in the history of your Glyphs file?
You can’t do this, unless you are using a versioning system. I highly recommend:
If you’re lucky, you might have a Time Machine Backup of the file.
OK. Thanks. I lost some changes in a sync between computers. Not onerous to redo, but slightly annoying.
I really strongly recommend learning the basics of git, and versioning all your projects in git. Light Table is a brilliant solution for this and makes it really easy and visual, directly within Glyphs. And it’s free, which, frankly, is criminal.