Good Morning,
I have a few stainless steel, full length barrel, complete parts kits including the receiver stub with the serial number (these are 192 series). There might be a small part or two that is blued instead of stainless, usually the exact part you are referring to. It seems that piece was replaced on all of them at some point in time. The stock is a black polymer Choate pistol grip stock that were installed by the original owner. They're in very good shape, bores are very nice. A prison system had these, I suspect they sat in racks mostly. The part with the most wear are the rear sight bases. The bases were originally coated or painted black, that coating seemed to not be too durable, it's flaking off like paint.
I've sold a few of these to Sturm members, all were happy. Ask around and you might hear back from some of them. They are $1200 plus shipping.
Thanks,
Mike
Smiths Speed Shop, Purvis, MS