There are several options for you to consider, F-Hole. There are many vintage guitar shops out there that could assist you, but for me, the best luck I’ve had when seeking assistance of this kind is via two main sources: 1. The 12th Fret guitar store in Scarborough, Ontario, Canada. They are an amazing custom shop (and have done work for the Rolling Stones among others). They can appraise the instrument and provide a history of the instrument. They are on the web at I believe, 12thfret.com. They actually have a vintage 1840’s Martin for sale !!
2. Alternatively, if you live in the USA, get the instrument appraised by Lark In The Morning, a world music/rare instrument store located in San Francisco. You can find them on the web at larkinthemorning.com. They can do appraisals for $50 USD if you send them some good photos of the instrument.

Regards and good luck from the blackmandolin !