This book, "Практический курс изучения древней русской скорописи для чтения рукописей XV-XVIII столетий", by И.С. Беляев, is a replication of a book originally published before 1907. It has been restored by human beings, page by page, so that you may enjoy it in a form as close to the original as possible.
This is still the best source for studying early Russian handwriting. Not as useful if you are interested in the eighteenth-century handwriting (despite the title very explicitly mentioning the 18th century), but still as useful as a textbook on such a narrow subject can be. Probably too dry to be enjoyed casually