Hmmm, that is indeed rare. I have never seen a short barrel revolver in the Teams. Granted 1969 was before my time. However, neither the museum room at NSWC Crane, IN nor the UDT/SEAL Museum in Ft. Pierce, FL have any of these on display, either.
In 1969 there were only SEAL Teams ONE and TWO. In the early 90's I saw many weapons that SEAL Team ONE had kept in thier armory from the Vietnam years in the warehouse at NSWC Crane, IN. ST-1 had been told to ship those old weapons to Crane and they were going to be destroyed.

They stayed there on a wooden pallet for a while until a way was found for many of them to go to the UDT/SEAL Museum. Some of the weapons were captured from the VC...crossbows, handmade firearms, and an M-1 carbine with bullet impacts in it. But, again, I've never seen one of these revolvers before. Interesting.
Frogman