Well I don't know guys? The gun does not have any polished flat studs, the side plate fit is great, I don't see any rounded edges, the markings appear all sharp, and the hammer and trigger are both case hardened, as they should. I'm wondering if the gun could have been damaged somehow in the grip strap area, or there was moisture under the grip that pitted the gun, but left the rest of it clean. I know that is unlikely, but if refinished, it looks good enough to be factory, except that there is not a * (star) on the butt.
OP, look underneath the barrel, on the flat, and see if there is a "B" before the SN. That was only there on blued guns, and if there is no letter before the prefix, then it at least shipped in nickel finish. I think the gun looks very nice, even if refinished.
Were the triggers and hammers on the nickeled M&P .38s always bare? I have one from the late 20s/early 30s that's been in the family at least back to the 40s, if not from new, and the trigger and hammer are both nickled. I'm jsut curious because neither my father nor my grandfather are the type to refinish a gun that still worked.
I never saw nor heard of a factory nickel gun with a nickel plated hammer and trigger. One way to tell is to look under the barrel on your gun, and see if there is a "B" before the SN on the bottom of the barrel. In this area, a blue gun is marked "B" and a nickel gun has no prefix, just the SN on the bottom of the barrel.