[squeak-dev] Help: Keeping in-image class schema version + persistent data version consistent

Looking for best-practice suggestions on this, with a goal of simplicity:

My image (specifically, the class schema in my monticello) evolves. I have
multiple repositories with snapshots of object graphs persisted, each from
some version of the image. At any time I want to be working with the latest
version of the image, across all snapshots.

What kind of version-related information should I save with (a) the image
(b) the persisted snapshots? What policy to use to keep these in sync? Would
some Squeak equivalent of Rails/migrations be relevant, and what might it
look like?

Thanks!

Sophie