After looking ar Nike Strietbeck's article, I recall seeing many years ago at some gun collector's shows, some versions of the Remington Revolving Rifle that I haven't seen pictured in reference books or on the web.
One version was a rifle with the NMA length loading lever rather than the usual longer lever seen on rifles, retained by an extended streamlined lug which gave the appearance of extra length.
Years ago, before Uberti made the reproduction, I built one from a Navy Arms revolver, and used that shorter version of the loading lever, I made the latch lug from a piece of steel that was at hand.
I noticed then also that the 36 caliber rifles had a hole drilled through the topstrap at the cylinder gap, presumably to help redirect gas upwards and perhaps reduce fouling at the forcing cone, or as a pressure relief. I never saw this feature on a 44 caliber rifle.
There used to be, back in the 1960's, in the East, a fair number of RRR's at collectors meetings, which do not appear these days, some 50 years later.