I have two of these- purchased a few years back.

Boxlock 12 bore with 90 % condition with origional case paid in the $5000 range

Boxlock 16 bore 100% rebuild in UK with origional case in the $6000 range

These are both true Martin guns. There seem to be very few of these in the US. The 12 is the best little bird gun. 16 is butt heavy but a joy to shoot with proper light loads.

al