That has to be an ultra rare variation. No wonder you couldn't track that down. Might even be a one off or prototype.
OK, so technically this is a non-recessed grip frame 3913TSW pre-rail, but it's the closest thing I've ever seen to a non-railed, caliber-marked 3913TSW. Yes, I tried to track this particular gun down, and no, I was not able to purchase it.![]()