I purchased what was supposedly a deardrof 8x10 back thinking that backs were pretty standardized and that it'd fit on my Eastman No.1. It does not. the interior lip that fits inside the rear standard is 1/16 to 1/32 to wide, both ways, and the overall width is about 1/4 inch too wide to fit in the clips - so, Should I take out the chisels and start working the "deardorff" back to fit? or should I try to see if there's anyone to trade with? I'd hate to irreversibly modify something that I shouldn't , but on the other hand, I really want to shoot some 8x10's of me family this christmas.