The only replicas of the Whitneys were made by the Palmetto company. There should be Italian proofmarks on it, and a company logo (I think it's a palm tree).
What is the serial number? I can check it.
The markings on your barrel top are the correct ones for an original.
The frames were made of iron - mine has a plumb brown patina to it.
Remove the trigger guard and look for the Whitney Eagle or other marks.
I shoot .380 roundballs out of mine with about 15 grains of black powder. I would have it checked before firing it if you don't know what to look for.
Thank you for a detaild and fast answer its not actually mine yet
Im thinking off buying it .The guy selling it says in the ad that it has at some time been re blued and
that the chambers in the cylinder are a little Over dimensioned and i sent a mail asking for the serial number