I've got a set of Binci brass based reeds on order, and I originally was going to put in my C Acadian of 2002... I'm thinking of putting them in my B accordion (which technically, is only a half step difference)... Then putting the B reeds in my older C accordion.

Do you think that I'll need to add wood to the chambers of my B accordion, since these are slightly higher reeds? Not as concerned about taking away in my older C, to fit B. I just don't want to add wood that isn't an exact match to the reed blocks in my (now) B accordion. Plus, it's a lot of work I don't really want to do

I would wait until you get the reeds. I doubt if many need altering, and good chance you won't have to do any. Very good chance the reeds are most the same lengths. What I've learned about reed making, they don't necessarily have C tongues, or B tongues, they may use the same reed, and just alter them differently.

Sacre bleu!
You guys are talking on this level and I'm still trying to poke at the right buttons!