Merging two fonts with kerning

I have two sets of Latin-Cyrillic masters that I’d like to merge. Problem is with the kerning. The other masters are done with split kerning (no shared groups between scripts) and the other masters use mixed kerning.

My first thought was to rename groups (eg. A to A-cy), but how then to rename the old group references in pairs list?

How would you recommend to go about merging the masters?

I would un-split the classes. Saves you a lot work. And is easier to do.

Ok, but exactly how do I un-split the classes?

Rename the classes of the glyphs (e.g. use “A” in “A-cy”). Then go through the kerning list and rename all classes to the new setup.
You can try to start in the kerning panel and rely of the automatic renaming.

Ok, thanks. I built a script to find/replace a list of strings with another list and ran it against the .glyphs file. It renames the classes in glyphs fine, but I can’t figure out why kerning classes are not renamed properly. For example, I replaced all instances of @MMK_R_Ve-cy" with @MMK_R_B" but when I open up the file it still has a kerning group named Ve-cy. What string should I target in the .glyphs file in order to rename the kerning group?

The keys in the kerning are with the @MMK_R prefix. In the glyph, it is just the

kernLeft = A;
kernRight = Ve-cy;