You have a way better chance finding a good working rifle with the JM on the barrel, than REM!It looks like there are at least 4 JM marked 45 colts on Gunbroker ranging from $800 on up. I wouldn't turn my nose up on a Remington made gun but only if I could hold it in my hands and look it over. I wouldn't buy one off an internet auction.
My JM stamped 357 made around 2001 IIRC was not smooth at all out of the box. Plus the buttstock had a tiny crack at the tang. Marlin sent a new stock but the color was different. I just spread the crack open and drizzled thin CA (super glue) down the crack and have been using it ever since. After taking the gun apart and smoothing everything up it is slick now. And it always shot extremely well. Just because its stamped JM is no guarantee its a perfect gun.
Is “sex change” the best description? More like “enhancement!”Good luck finding one. I had to make my own.