Some years ago there were several books authored by JB Wood on
firearms assembly/disassembly and one covered .22 rimfire rifles. The
Ithaca 66 was one of the rifles included in the book. The books were
Gun Digest publications and you might be able to search online and
find the info on the Ithaca 66. I have a copy of the book on .22 rifles
around here somewhere and I'll try to find it if you can't find anything
online.