Howdy Grapeshot,
I think the weak point of this model is going to be the cylinder, not the arbor. The metal between the cylinder holes and the bolt notches is paper-thin. I have seen .45 S&W OT with the metal bulged out at this point, and have heard of others that have blown out there. And of course .45LC is more powerful.
I'll tell a little story about Cimarron and the .45LC OT. A European CAS shooter named Scattered Thumbs informed me that Uberti listed the OTas being available in .45LC on their site
www.uberti-replicas.com . I pointed this out to Mike Harvey, who was unaware of it, and he looked on his price list from Uberti and sure enough, they listed .45LC. So Cimarron ordered these from Uberti and even put .45LC as an OT caliber on their website. This was a couple years ago. Later that year when Mike was at Uberti for his annual visit, he and Uberti both decided that .45LC was not a good idea, so they dropped plans to make it and that caliber option was removed from Cimarron's website.
Fast forward to mid-2006, when Cimarron's 5-year exclusive ran out on the OT's and R-M conversions, and now Taylors and others can order them. Uberti never removed the .45LC option from their pricelist or from
www.uberti-replicas.com - Taylors sees the option and says hey, we want them, so Uberti builds them.
Those guns are made out of very good steel, but I would still be verrrry careful of what I loaded in one!
By the way, I think these would be awesome guns for mounted shooting with blanks, since they point so well and have that short hammer pull.