I was just kidding martin - trying to suggest that it's actually (probably) a really good lens and you shouldn't even think about getting rid of it unless your prints are definitely lacking relative to other lenses you've used. The other thing we never looked at is the enlarger... if you're using something like a beseler - I could easily see the focus shifting just from turning the diaphragm...

oh - but i guess it's a devere - so NO chance of lens board movement... I have a 504 too...!