Should be pointed out that, if this is part of the estate sale you are enquiring about prices for elsewhere, then if there are any interested beneficiaries that revolver should qualify for a 12(7) inheritance to a qualified beneficiary. The value of that piece (unless as I say above, it should somehow fall into "antique status" by virtue of an unlikely rimfire chambering, coupled with a pre-'98 manufacturing date) would likely be greater in sentimentality than on the limited open market for 12(6)s.
Worth considering
Good luck