I would have to agree with the rest. I've only been at this game for 40+ years but I have been at it as long as this style, relieved, non Diamond, Targets have been made. I've owned a a bunch of guns and probably 100 sets of grips and seen thousands and have never seen any factory shipped grips in this profile.
My bet, especially seeing they all came out of the same collection, would be factory issued Targets that were altered and refinished after the fact by the owner or his smth. A very nice job but.....................
Way back in my uniformed LEO days we used to routinely round a 45 degree chamfer of the bottom edge of Targets grips. It kept the bottom edge from getting banged and chipped constantly. Okay, we also thought it looked cool. ;-)
I sold some over the years and made sure to tell the buyer that they were modified factory grips. Years later I ran across two guns I KNEW I had owned and sold with the seller telling the story that they were some kind of RARE factory modified target grips only available to LEOs on special order!!! What a crock. When you asked for proof one guy said he bought them from the LEO who told him the story. The real liar said they lettered that way. Yeah right.
Interesting and well done but not factory.