You have 2 options. An N frame 357 reamed to 45 colt or a 41 or 44 mag cylinder. All of them will require the frame lug to be trimmed back as the 45 acp cylinder is about.04 shorter in the rear and lug of course is longer to prevent excess movement when cylinder is opened. I you use a recessed cylinder lug will need trimmed more to accommodate recess portion of cylinder. This can be done with patience and a file that has no teeth one side not cutting lug. Some duct tape to hep keep from marring frame is a go plan. You only want to be filing leading edge of lug.
If you use a 41 or 44 mag cylinder the barrel portion that sicks into frame window will need to be trimmed about .10 also as those cylinders are about that much longer on forward end. Trim to get that .004-.006 barrel to cylinder gap, then recut forcing cone.
A 455 cylinder reamed deeper to 45 colt would also work. You would also need to recess it or face the rear of cylinder off about .022 as the 455 has a rim that is about.040 thick while the 45 colt and other revolver rounds have a .060 rim thickness. But, good luck finding a loose 455 cylinder.
I have made several 1917 and Brazilians into 45 colts. Even a 1955 45 acp. I have also made 629-1 into 45 colts using 45 acp barrels and reaming their 44 mag cylinders to 45 colt and trimming barrel shanks. Big time 45 colt fan. Have 7 of them. The only one that started as a 45 colt was 8 3/8" 25-5 but it had the large cylinder throats like most early 45 colt cylinders so, I reamed a recessed 44 mag cylinder and while I was at it cut the barrel to 5"
A pinned and recessed 5" 45 colt
4" & 5" using 629-1 frames and reamed cylinders
converter to 45 Brazilian using a cut down 1950 barrel and 44 mag cylinder