I had a similar problem with my Beretta due to a previous owner cutting some length off the stock. I actually needed about 2", so I used a couple of these:https://www.ballisticproducts.com/Black-Buttstock-Spacer-Flat-1_2/productinfo/1513112/
I think I used 2 of the 1/2" spacers and a grind to fit recoil pad that adds an additional inch. The spacers are glued together and then the recoil pad was glued to them and the whole thing ground to fit the stock. It attaches to the stock with 2 woodscrews, so I can restore the original pad at any time, though I will never do that as long as I am able to use the gun.
The spacers look like part of the recoil pad, though I wouldn't say that a 2" recoil pad looks exactly right. It works, and I don't think the doves know any difference.