Claybuster,
The action body on your fine old Holland gun appears to be the, Alfred Lancaster patent number, 1525 of 1865, less the retractable firing pins.[see page 189, British Shotgun ] The locks and hammer profile are typical of those seen on early Lancaster guns. In view of the patent use number, it would appear that a working relationship existed between Charles and Alfred Lancaster despite the family split.
In the Era that this gun was made it is possible that the gun was bought in by Holland semi finished or possibly finished, with Lancaster's a possible source.
