SW I think we have managed to identify the error on the Captains Register for Hugh Duncan 1888 No 102973.
The original Cert No 25688 issued in Liverpol 1st Dec 1868, when the nancy brysson was lost in 1876 another Cert 02973 was issued again in Liverpool 10th Feb 1877 - I have the copy of the new Cert together with the declaration detailing the loss of original Cert with the ship.
When I saw the BT microfilm the number 102973 just jumped out and how easy it would be to add a 1 to 02973.
I can now go along to the Maritme Museum in Liverpool armed with facts and photographs .
I'll keep the forum updated on any progress