Thank you for the responses. Numrich has none. Ditto for S&W and Midsouth. Brownell's shows them as in stock for the 17-4 but I had to send it back as it was for a newer version with a rounded front on the leaf/tang. I need the squared off front. There is one mounting screw but there are at least two versions of where it is located. Rough Country makes a very nice but very, very pricey sight for the 17-4. Because of the variations in the mounting hole placement they won't drill the mounting hole, for which there is an additional charge, without being sent either a sight assembly known to fit the gun (guess that would work if I had one and wanted an upgrade) or exact measurements (can't return it if you get that wrong). The search goes on. I'll put a WTB in the classifieds.