Bear Tooth Products (www.beartoothproducts.com) makes a comb raising kit that several OG members
use. They come in brown , black and some camo patterns.
They come with several thicknesses of foam pads to raise the comb height...the thinner ones are only about 1/4". You can use any combination.
If you just want to cushion the cheek slap some the neoprene sleeve and a thin pad or two will help.
The foam pads are dense enough to sand on a belt sander to shape/taper to fit your stock. I glued two pads together with a contact cement type adhesive befor shaping. This helps the sleeve fit tighter to the stock and looks better.