I added two pictures, one with what appears scratch marks on the barrel which may have obscured a serial number. The second picture, although difficult to see, appears to be some sort of hallmark.

Please let me know when you receive this
Thank you very much
BJ Thomas

Dear Thomas,

Thank you for contacting Mearto with your appraisal inquiry. My sincere apologies for the delay with the appraisal.

The presented object appears to be a Derringer single-shot gun. It has no make mars and was common in the middle and second half of the 19th century, especially in the United States.
Comparable objects were recently offered and sold on the international auction market.
This piece is in medium condition and no severe damage is visible in the images provided.
A fair market estimation would be between 100 to 200 USD.
This estimate is based on actual recent past recorded auction sales of comparable items. Retail "asking prices" can be higher and may vary.

With kind regards,
George