Difficulty reinstalling Savage 1907 breech plug

I brought the breech plug from one of my Savage 1907's into a local shop to get the extractor claw replaced, and now I'm having trouble reassembling it back into the rest of the gun. It inserts just fine, but doesn't rotate far enough. My other 1907 is identical as far as I know, both the military variants and about two months away from each other coming out of the assembly line. I'm not seeing any differences when comparing the various bits.

Anyone have any sort of "jiggle the handle" tips?