Follow Up:
We thought those of you who contributed to the discussion and research on this Fred Adolph 20 gauge would be interested to know that this gun and case will be presented for sale in Rock Island Auction's Premier
Firearms Auction on August 27, 2023. Here is a link to the listing:

https://www.rockislandauction.com/d...-20-gauge-boxlock-double-barrel-shotgun.

The pre-auction estimate range seems consistent with the valuations discussed on this thread (of course without the benefit of actual physical inspection). They provide an in-depth description in the auction catalog.

Thank you all again for your kind assistance and contribution to our research on this family heirloom. Let's see how it does on the day.

Cheers,
Tim and Tim