Wingmaster 870 Recoil Pad replacement

[Virginian]

You're going to need to get the stock cut and a recoil pad re-fitted. The profile of the Remington stocks with and without recoil pads are different. If you are handy, you can try it yourself, but I don't do well with wood myself, and if you screw up the finish re-fitting the pad it's a major hassle. A gunsmith will usually charge less than $50.
Or, as an alternative, look for a Remington wood youth stock. They did make them and if you look around you can likely find one that pretty closely matches what you have.