I believe the ones I have bought from the dealer have always been rebuilt. They usually charge a core charge-refunded on return of old caliper. I have never had any trouble with the calipers I bought at the dealer, but they aren't cheap. You may be able to get a better price from Phil and he stands behind his stuff. Btw, seems to me the front calipers on my 126 were two piston and the 107 were four piston. it's been awhile since I had them apart.
BobK