Hi

> But I've never seen any comparable work on Cyrillic. Almost all I know
> of historic Cyrillic writing is what I've seen in ornamental use. Can
> anyone recommend a book or a website?

It is true that it is difficult to find books about the evolution of
the shapes of Cyrillic letters, even in Russian.

Maybe you want to have a look at books about Old Church Slavonic.
After all, most letter shapes had already been stabilised once Russian
took over.

Priviet,

Gianni