Guys, what types of stocks are/were used on K-frames, like my 14-2, when shooting bullseye competitions?

I'd like to get a set that are very hand-fitting, compared to the standard target stocks that are on it now. The only catch is that I'm left-handed.

I was looking at two different models of Nill grips. The left-handed version of the Nill model SW04P8 (here) and also the adjustable match stocks, model SW043L (here).

Now, the biggest question with the second set, SW043L, is how in the world does one thumb cock the hammer into single action with that beavertail resting between the thumb and forefinger, apparently blocking access to the hammer? Are those grips intended only for double action? I thought for sure that most shooting with those types of hand fitting grips was done almost exclusively in single action.

Any other ideas would be great. I've been looking for an older set of Herrett target stocks, but so far I've only found right handed versions.

Thanks for any pointers!
Phillip