Grantr, I was wondering what caliber yours were, I am hopinng to get one in the next 6 months and was figuring .45 LC!
Mine are chambered for .45 Colt, which is my "universal CAS cartridge". (It was what I already had from my days of black powder shooting before I shifted into CAS, so I've stuck with it.)
By the way, the lanyard rings are something that no reproduction Model 1875 Remington has ever been offered with to my knowledge, even though they were very common on originals and were shown in most of the period Remington promotional illustrations -
I've never particularly liked the looks of the Model 1890 Remington, which Remington tried to make look much more like a Colt, but Uberti do make their "1890 Police" repro with a lanyard ring. Since I really like revolvers with lanyard rings, and wanted to make my pair of 1875's somewhat unique, I ordered swivels and rings from the Uberti parts list and installed them on my 1875's several years ago. (Actually, although I received the swivels right away, the rings themselves were on backorder for more than a year before I finally just made the rings myself. Didn't cancel the backorder ..... but also never did receive the rings!)
By the way, the Model 1875 is not strictly " a cartridge version of the Remington 1858 Army cap and ball", nor a "cartridge conversion" of that model. Although it does resemble the Remington percussion revolver (primarily because of the under-barrel reinforcing web, which is what gives it its "charm" and which
resembles the Remington-style loading lever) it was designed and marketed as a new model. Also, I don't believe Uberti themselves offer a cartridge conversion version of the Model 1858 - you'd have to acquire a conversion cylinder from one of the separate manufacturers of those, and install it yourself.