I put a straight edge on the Z frame and felt that the cut-off part ahead
of the fold was ever so slightly high. My top lid was a little raised as
others have described. I dressed the cut-off part down very slightly and
now the top lid fits quite nicely, almost perfectly. I sent an email to
Elecraft suggesting they look and see if the Z frame is within dimension.
My KPA500 is SN 0691 and I just finished the kit the second week of