Benelli Nova 12ga S&J +3 tube extension

S&J Hardware +3 12ga nova magazine extension. Allegedly fits Girsan MC312 & Beretta 1301. Got it with a nova purchase but don't want it. Seller said the retailer told him the spring needs to be trimmed down an inch to fit the full 3 shells. Can be fit on as is but is somewhat difficult. Comes with bits in photo. Shown in 18" tactical model.

Local preferred, shipping on buyer