Namely, spend about 45 minutes browsing the USFA website. Because when I did, I found their “Lend-Lease” Colt SAA reproduction, which is a Colt SAA style revolver chambered in .45 ACP. This is a historically accurate revolver, as well – it seems at the start of WWII, the Brits were off in a bad way for small arms, and pretty much took whatever they could in terms of pistols. Among those pistols sold to them in the US Lend Lease program were 161 single action Colt revolvers that had been chambered in .45 ACP.
The guns that USFA makes don’t really fill a niche for me – I don’t shoot CAS much these days, and I don’t have $1800 to drop on a gorgeous hand fitted revolver. However, like many things in the world, they are worth that price to certain people, in which case you’re probably not going to find a more attractive single action revolver.