Rawcliffe were one of several companies that made gaming miniatures for the FASA Star Trek role play games from the 80s. When FASA stopped producing those games, Rawcliffe carried on making model ships and figurines under their own license, well into the 90s.
Rawcliffe were one of the first companies to go big for starship models. Their initial offerings were pewter models of existing FASA miniatures of TOS TV and movie era ships (including some original designs), but as they grew their own range they added in TNG miniatures; using FASA designs for an unproduced TNG game, never released by FASA themselves. Later they also included ships and characters from DS9 and Voyager, and started creating larger models too. (See Memory Alpha for a longer history lesson).
This Enterprise is based on one of the later more elaborate models, product code RF1777. The original version also featured a gold coloured (but not actual gold) deflector, and translucent red bussard collectors, but otherwise was, like most of their range, made of pewter.
To create this bespoke silver version, Schwabe adapted his original model created for Rawcliffe (with their consent) to make it suitable for casting in silver, which included hollowing out the base, and also created new molds for the nacelle caps. He had two castings made and assembled them himself, with one of them purchased by Rawcliffe, and the other he retained. Until now that is; Schwabe has decided to sell this unique piece, which is how this story came to light, and why we have a great set of photos to admire his creation, via his Ebay listing.
For reference, here's a look at the original pewter retail version:
According to Schwabe, Rawcliffe's vice-president for sales told him they would look into marketing the precious metal version. But the project was never picked up. Maybe it just wasn't really Rawcliffe's thing though, aside from one gold-plated Enterprise-D model, they were pretty loyal to pewter as a material.
Possibly there were also conflicting interests at play, as around the same Rawcliffe's regular USS Enterprise was released, Franklin Mint launched an entire range of solid silver starship miniatures, including the USS Enterprise and eleven other ships!
Latterly silver starships are more common than you might think. Just a couple of years ago the New Zealand Mint came out with the latest silver USS Enterprise miniature:
And slightly odder, just a year before that the Royal Canadian Mint created this curious USS Enterprise "coin", which does on the underside have the head of Queen Elizbaeth II and everything else you'd expect of a Canadian coin, including a face value of 100 Canadian dollars - Made from ten ounces of silver, it sold for significantly more than that.
Mark Eliot Schwabe's unique silver and gold Rawcliffe USS Enterprise can be found at auction on Ebay right now, and all the other items are available on the secondary market from time to time, if you're feeling like amassing a particularly lavish fleet!