hey, like we always say, "with Ruger, never say never...." I'm sure Chet15 will see this and comment on it,but "parts is parts", and not so noted on the shipping invoice......
special order, could and should be noted...........besides the fact, it could also have been returned to have the the Micro put on...gotta have the "paper trail......" even if the original buyer, claims he bought it this way, we have seen shops over the years , put other parts on guns, just to make it "different" from another one that may be "identical" on the shelves,,,,see this more often with grips, but not really a reason for them to 'swap out' an adjustable rear, again, it is a case of shooter preference...........