Joe;
Thanks for that patent link. I will have to look at mine real close, but I don't recall noticing these joints. They must have turned the barrels in from the center so the joint would be invisible after the top rib was installed. Mine was a heavier gun, 30" @ 7 lbs. it has a leather covered cheek piece with the comb hollowed out beneath it & filled with what appears to be cork. I got it as a project gun with forend missing but have done nothing with it yet.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra