I couldn't find the old thread anymore but wanted to say thanks to all that
advised me and let you know what happenend.
Recieved new 557 from Amazon. Got it out of the box. Cut a slot for a
number 20. I was so confident, I went ahead and glued the slots and the
biscuit and slipped it in - with seconds it was almost to snug to remove.
Much better. Somehow the original machine simply was cutting ovesize slots.
It almost had to be runout, after taking a dial caliper to the blade tips
and the biscuits (they seemed just fine) - I don't have a dial indicator.
Anyway - thanks again guys. Problem solved.