This is an excellent choice that slipped my mind as well. I have one made by Pachmayr (I believe it's been a while since I bought it) Leather with multiple inserts for lengthening. This has been a valuable asset to me as I take a long LOP 15-15 1/4" comfortably. This might be a bit more expensive but can be removed/added at your convience. Can also be used on multiple guns. Just remember to remove it for long term storage as some guns carry the distinctive mark of wearing one for too long.

Double guns and English Setters