My daughter shot a Thunderer in .357/.38 for SASS for about a year. It was a great pistol. I recently traded it, however, to another pard as an even swap on a pistol that matched her second pistol, an AWA Birdshead in .357/.38. The funny thing is when I got the "new" pistol home, it was a consecutive serial number to the one she already had. Small world.
If I'm not mistaken (which I can often be), the Thunderer is a "not entirely" correct repo that took the Colt Thunderer as it's inspiration. The original Thunderer was one (if not the first) of Colt's first attempts at a double action pistol. I think the original Thunderer was in .41 caliber.
T6 a/k/a Chick