
Reproduction “hard rubber” (I put that in quotes because I am pretty sure these are actually all modern polymer castings) grip sets for Remington single action revolvers are offered by:
Vintage Gun Grips (vintagegungrips.com … $41.50 + $16.00 for hardware),
N.C. Ordnance (gungrip.com, $35.00, says most grip sets include the hardware, has a downloadable exact size template to check against your frame, but the listing says the grips do not fit the Uberti 1875)
Hand Gun Grips (handgungrips.com, 29.95 … might be out of stock, but the site let me add them to a cart, so I think it may just be the separate hardware which is out of stock - if so, you could probably use the escutcheons and screws from your existing grips.)