Than for all the info. I saw 3 go on eBay earlier this year, and I bid on each one (Ending within seconds of eachother due to the same seller), and I got sniped on every one of them :/
They're tough to obtain - I managed snagging one last year, but it wasn't all that cheap.
The good news: aside from the back design and jokers, the Gold Seal Bicycles are IDENTICAL in performance to the Gamblers. Both use Bee Casino stock and are traditionally cut with standard USPC faces.
The bad news: while they're still around and fairly cheap (I think Tannen's still has them for $4.95/pack), the Turner Gold Seal Bikes are out of print and will eventually run out.
The better news: CARC's Professional Bicycles in red are identical to the red Turner Gold Seals! Same stock, faces, back, finish - only the ad cards are different. CARC only used Magic Finish on one deck design in three variants, and it was the only deck they made with metallic ink (unless those new Skull-and-Bones Pro Bikes are metallic). They don't come in blue like the Gold Seals, but you can't have everything.