I have an original (non-finger-groove) Pachmayr stock on one of my SBH's. Comparing this to a factory-original SBH, the Pachmayr stock is narrower (port to starboard) at the heel, and wider (fore-to-aft) overall, as it covers the entire grip frame and includes a little extra material to fill the "squared" area of the trigger guard.

It is an exceptionally ugly stock. But what it lacks in that department, it makes up for in comfort.