I sent photos to Bill Adams in CT---he provided me with all kinds of info on various re-converting signs --in the end he gave it his blessing.
I have dealt with Bill before regarding my possible CS P53 Enfield rifle musket----Google him and see what you find.
One of his comments;
It's tough to point out what to look for on a good reconversion. Amateur reconversions are easy to detect. Most of the M1816's were converted via the cone in barrel system, usually called a Belgian conversion. Those are the prime candidates for conversion back to flintlock as they seldom are as costly as bolster conversions.
Assuming that the conversion to percussion was by the cone in barrel method, the reconversion is accomplished by removing the nipple and peening down the raised/displaced nipple seat metal. The remaining hole is then welded in with soft iron. Many hacker gunsmiths use regular steel welding rod and occasionally someone actually uses stainless steel rod to fill the hole. After the welding, the metal is dress down to the proper curve and the barrel is then either polished or artificially patinated to blend in the repair. As the polished barrel ages, any welding done with steel rod or stainless steel shows up as a round or oval spot that is too bright. A real craftsman who uses soft iron rod can blend the finish so the weld cannot be detected.
Some persons merely thread a screw of the proper thread size into the nipple hole, then file everything down and tap the edges of the screw down, then finish the filing and stone the surface. Those reconversions can be spotted easily unless the hacker artificially pits the repair area.
When the arms were originally converted to percussion, it was common to mark each component piece with an alpha-numeric code like A3, B24, etc. Less often, just a letter or number was used. The bayonets were also numbered to mate the musket. The small bayonet lug on the top of the barrel was also numbered.
It's very difficult to find original flintlock cocks, frizzens, and frizzen springs. The reproduction parts are castings and the surfaces are seldom as smooth as original parts. The frizzen springs will look newer than the lock plate and the frizzen spring mounting screw and the hammer/#### screw will have slots that are too wide. Flintlock era screwdriver blades were much thinner than modern screwdriver blades. Reproduction screws are usually made with larger slots.
Make sure that the pan fits tightly against the barrel and that the flash hole is slightly above the bottom of the pan. Look at the pan carefully - it should not look new or have any obviously file marks.
Look down the barrel - sometimes there will be traces of rifling; remember, the rifling was progressive depth and was very shallow at the muzzle. Some reconversions were done on 1816's that were rifled when they were converted to percussion.
Those are only the basics.
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I forgot to mention that many flintlock muskets were converted on the "drum" system. The reconversion is often done by simply cutting off the percussion drum. Sometimes a circle can be seen around the flash hole, but it doesn't take much to hide that. A gunsmith friend has done many reconversions for collectors and cautions them against passing the pieces off as original. He does work for museums and wealthy collectors.
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Bill's conclusion;
The musket doesn't have the usual conversion stampings and looks to be a nice piece. It looks like a good acquisition if you can trade into it.
