You own a rare and stunningly beautiful piece of Parker history with wonderful provenance. Like many rare collectibles, the only way to truly know it's value is to offer it for sale in a well publicized venue. If it were mine I would have it insured for at least $75k. The butt pad is a pretty good sized wart. I'm not suggesting that you would realize that in a sale, but the likelyhood of finding another one is small.

If it were mine I'd find a period Silvers pad, or a new reproduction to put on that gun.
Anything to replace that white line Pachmayr.

Awesome gun otherwise.

Butt Plate
 

Now I have another question to answer about the gun. I will keep you posted.

With respect to the advisability of retaining or replacing the white line shoulder pad: Has Rich Sterns indicated unambiguously that he is seeking the Parker gun’s value preliminary to selling it? Or is that something that goes without saying, given the unmistakable signs, as recognized by advanced Parker collectors?

Anyway, fantastic provenance, as said, and not the first time we have heard of a gifted high-grade Parker being retained, unshot, unused, but placed in long-term storage out of gratitude and respect by a family member whose interest was in sailboats and sailing, not guns and gunning.