Could you pleasure us w/ a few images of the marks on the water-table & on the underside of the tubes. Regarding combination longarms for mixed bag hunting, the 16 bore was the basic platform which was scaled up or down to meet the clients needs in multi-barreled longarms. The O/U typically has the rifled tube as the lower tube in the proper plane so I would say it would be a more accurate combination vs the Cape. Also, on the Cape, the position of the rifled tube, left or right, was determined by overall use. If the rifle was used more it would be on the right w/ a single set trigger.
Cheers,
Raimey
rse
Once I get the gun in my hands I will post more pictures. This gun is currently in Germany.