True, there were not thousands of these.

But they're nothing particularly outstanding.
I owned one, bought new for about $350, if I recall right.

It was ok, nothing overly special, played ok, sounded ok. It did look a little better than other "MasterClones" of the time.

If you can find one reasonably priced, makes a good entry-level bluegrass banjo.
 

A late friend of mine had one of six (I believe) prototypes of the GTR banjo. The prototype did not have the GTR logo on the peghead. This friend spoke to one of the principles (not sure which one) who told him there had been a theft of the prototypes. This principle said that he knew where some of the banjos were and then said, "And now I know that you have one". The friend loaned the banjo, with a strap that Grandpa Jones gave him, to a local museum. The banjo and strap were never recovered after my friends passing. Have another friend that has a GTR. This GTR was set aside when he obtained a "Celebrity" model from the late Arthur Hatfield. Just a little evening story.

I've got one branded "NMI" on the headstock. Literally the only picture of an NMI banjo I can find on the internet is of the Craigslist post (also listed on Reverb. Same banjo) of the one I bought. From what I gather from some guitar forums "NMI" stands for Nashville Musical Instruments and was a music shop a block down from Gruhns. I can't find anything about them putting out a branded banjo so I could be wrong.

GEorge, Tut, Randy: GTR. Same as NMI, imports. IIda similar.

The Fender Leo was pretty much the same banjo.

Sometime in the early 1990s, I saw a GTR with all of the inlays in multi-color abalone over ebony and outstanding neck wood with outrageous flame in a local pawn shop for $550. I called George Gruhn, asked him about it and he told me that some did ship like that but we didn't go into numbers. When I mentioned that the asking price, he allowed that was a pretty good deal but that he wasn't interested.

That shop also had a Muse/Ode Grade 0 (one-piece mahogany) long neck, aluminum flattop in a Lifton case for $190. I was so surprised by the price that I didn't even try to get the owner to eat the CA sales tax. Still have that bad boy.