Just as an aside on using old lenses on Canon EOS. I bought an M42 to EF adaptor when I first had the 300D to use with some of my old M42 Pentax lenses. It worked OK but the main problem I found with the small view finder view and old age creeping up on my eye sight was the lack of focus confirmation.
I bumped into this artical a few months back. It looks quiet niffy and I have no idea where you would source it.
http://bobatkins.com/photography/rev...g_adapter.html