I have seen a M1917 converted by using a .357 mag cyl that was rechambered into .45 Colt. That got around the rim issues, the .357 cyl will fit in the 1917 because it's similar in length, and you keep the .45 ACP cyl the way it is. It's a straightforward conversion, so it's not an exploration into the strengths of case heads, or the wisdom of headspacing, gluing spacers, or anything else. You just cut the cyl for .45 Colt and fit the cyl to the gun. Simple and does what you want.

That said, I don't think you can safely load the .45 Colt to high enough pressures to take advantage of the larger case in the 1917. Heck, you can't even load them hot for a modern M25. So you end up with a .45 ACP class cartridge with a rim. Since the .45AR pretty much does that, you can just use the money that the conversion would cost and buy .45AutoRim ammo.

You can do the conversion, but there isn't much you're going to gain from it. IMO not enough to justify the cost.