I have a beautiful vintage set of Stag Ajax grips -- with even colors and nicely matching bark on both panels -- that are marked for the Ruger New Model Blackhawk, S Six, Vaquero or others.
It has a # -- but it says 31, not 50. (May not be the right package?)
Tried them for fit on my 1985 Ruger Old Army and they fit great, but I am not sure if I will use them or not... (Got them from my late father's estate -- he bought them for his Old Army -- but sadly never got to enjoy them... And I feel sorta funny about using them...)
If you think these may fit your Vaquero, send me a PM with your e-mail address and I can mail you some pictures.