Just received a Citori Trap with an after market Graco adjustable comb through an online auction. The gun was manufactured in 1987, not sure when the comb was done. The stud nuts are frozen in place with epoxy(?). Lateral adjustment of the comb isn't possible. Please look at the pictures. Can anyone tell me how the brass inserts attach to the stock? I'd like to free up the inserts and, if possible, counter sink them further to allow flush fit of the comb to the stock. All opinions welcome. Photos or diagrams of this hardware would be helpful.