I have one of each though mine are on Colts, But I'll echo what the Others state.
The gated Kirst does make the 51 Navy sweet to load , and the engraved R&D ( not sure if that is still a option ) is right at home on my Second Gen 1860.
BTW, I've had the 1860 38 years, the R&D has been it 11 of those years.