Bingo!
Yep, one of the hinge lines was cut about 1/8 of an inch too high. Looks like ours were cut on the same jig?

I'm at 7 1/8" cg now, and it still seems nose heavy to me. It pulls very slightly to the canopy on knife and downlines, but it requires a fair amount of down elevator even on 45 degree uplines. Has anyone tried adjusting the downthrust on their excelleron?