The 2100 and Recruit? No way. Inside of the Recruit/66 is just like a 760.
Old metal 66 recever and Recruit? sort of, but you lose the mag/clip feed port if you use the old part on a new gun.
Recruit and 760? Oh yes. Very interchangeable.
When he gets that mill he can make me a billet aluminum 760/66 receiver that uses those aluminum clips! MMMMHAHAHAHAHAHAHA!!!!!
I plink, therefore I am.