I am seeking information on a Winchester Model 21/16 gauge double barrelled shotgun w/single trigger/button select, serial #11838. Inherited this gun, last fired approx. 1975, in good used condition (original blueing, shows some wear on wood), would love to know about how old it is, value, scarcity, etc. Have been told this is a scarce piece, valued at several thousand dollars. If I need to insure, etc., I need more info. Have no plans to use it - it was grandad's - but want to make sure I preserve/insure/do whatever I need to do to keep it correctly for next generation. It has its original leather case, showing some wear, marked 72D/28. Any info will be greatly appreciated. Thanks.