The stocks on your 15-2 snub will swap with any other K frame except the Model 12 Airweight.
Snub 15 stocks would be diamond center with rounded bottom (aka PC Magnas),
The thing that makes the snub 15 frame different is that it doesnt "Step" down where the frame meets the barrel rib , this was done because the short barrels FS ramp meets the frame with no rib between, this is also why they used a long rear site leaf that goes right to the front of the frame.
Interestingly that long leaf was also used on the snub 19-2 when it was introduced as well as the later 66 snubs.