Jon;
Cool gun! It has the high horn stocks that usually came with the Centennials (models 40 and 42), but they may have been put on Bodyguards also. I can't recall seeing one, though, but my memory is bad
I would think with a pinned barrel, chances are the stocks would have numbered to the gun, but if you post a partial serial number or know the year it was made someone will be able to tell you.