I have the older Pietta "Shooters Model" which was made in 1986 and known as the "Deluxe Model", NAC#DRR 044. They were introduced and sold by Navy Arms Company, whose name sits on the top flat. Val Forgett, founder of Navy Arms, was a huge supporter of the US Muzzle Loading Team for the International Muzzle Loading Championship matches. He introduced the "Deluxe Model" as a full-frame revolver. When a regular Remington was $125, the "Deluxe Model" was $350.
To some degree, it was like comparing a Colt "Gold Cup" .45 ACP with its "plain-Jane" sibling, the standard out-of-the-box Colt Government Model.45 ACP.
Prior to the introduction of this model, I believe all the Remington copies made in Italy were made to the same dimensions. It was referred in some circles as the "two-finger" grip-frame back prior to 1986. The Remington "Deluxe Model", was popular with competition shooters. It more closely resembled the dimensions of the original Remington grip-frame AKA "the three-finger" grip.
When Val brought out the Remington-style revolver in 1960, he purposely had the grip frame altered to a smaller size to give collectors a relief, spotting a counterfeit Remington.
After the Remington Deluxe Model came out in good numbers for the competition crowd, Uberti decided to match the Pietta's frame size to theirs, so probably after 1990, most all of the Remington-style revolvers made by the Italian makers sported the larger grip-frame that we all know today.
The reason for the high price on the Pietta "Shooters Model" is the manufacturing & labor costs. Internal parts are smoothed out, cylinder has cutouts around the nipples for a Tedd Cash capper, front-sight is dovetailed for windage adjustment, and the barrel has a gain-twist barrel designed for the .457 RB. Among competition shooters, this model ranks third or fourth in the world behind the two German-made Hege Revolvers, selling between $1,200 & $1,700. The Pietta "Shooters Model is usually identified by the dovetailed front sight and the silver-plated triggerguard.
AFter 15,000+ rounds, it still holds a good group at 25 yards offhand with 18 grains of Schuetzen 3FG black powder, cream of wheat, a Hornady .457RB topped off with T/C Bore Butter.