Referencing the DHL Back book the Mantons 1782-1878 it lists serial number 6324 as a double barrel 17 bore Flintlock originally made in 1817 (p43)
If this is the same gun it is a significant conversion. While the book describes cases of conversion from flintlock to pinfire by Westley Richard’s (p 113, p 121). Further given the details in the book on the gun, I.e. 28 inch barrels, I doubt it is the same gun described.
Unfortunately neither the book or its supplement discusses in detail with pictures flintlock to pinfire conversions.
