urdobob,

Hello! A belated reply, and congratulations on picking up the fine Boss double rifle. Sounds like you have found a rarity in the firearms world indeed.

Short of contacting any of the big name, well-known auction houses in the U.S. that handle rare and antique firearms--for an appraisal fee--have you tried contacting Boss & Co. Ltd. in London? Perhaps they could help you in arriving at a proper and correct valuation for your firearm, or else point you in the proper direction to someone else who may be able to help you. Their address is:

Boss & Co. Ltd.
16 Mount Street
London W1K2RH
Tel: +44 (0) 20 7493 1127
Fax: +44 (0) 20 7493 0711
E-mail: info@bossguns.com

There is also a Boss Owners Club. Their website:

http://www.bossguns.co.uk/ownersclub

Hope some of this might prove helpful to you. Good luck and good show!

Best regards,

"LightningTwice"