RB,
Again, I am not associated with the seller but I'll tell you what I know about 101's. Early production 101's had different extractors, machining of the breeches, and forearm irons, and do not interchange with later models. That said, Pigeon Grades did not have factory chokes till late production and by then I think the forearms, extractors, and breeches... as far as I can tell.... are the same as the Diamonds.
I have several DG's including an ungun and it appears from the photos that yes, those tubes should fit a DG reciever with possible gunsmith fitting necessary. They look identical to me.
I'm not 100% positive but pretty sure. Hope this helps.
KEEP SMOKIN' EM.... Dave