Geo,
The lefty safety buttons from the Upper Sandusky people and the unit sold by Brownell's both work in older guns. I put a Brownell's safety in my 1957 model 37 with no problem. No problem, except, it is a funky gray color, and the gun is blue.
John, I've got a Remington model 17 and I know what you mean. For what it's worth, Mine is a 1933 vintage gun, and every model 17 barrel I've ever tried (about three) worked fine on it. I picked up a second 26" modified barrel off Ebay a while back, and it works perfect.
Best,
Ted
