Hello,
This is a bit late, but I think under the "506" number, I can see the remnants of a crown over "R" mark and a couple letters, though they are hard to make out. It's an oddity that I have seen on a couple of these bayonets that I am left without an explanation for. I have one with similar markings, but not a single French mark on it. On asking around in forums, I was told that it may have been a Belgian made 1842 bayonet copy (possibly for a minie rifle) for export. Where it might have been exported to, I have no idea. Here is mine. It might be a little hard to make out, but I think you can make out the similar markings here on the pommel of mine. There's also a crown over "R" mark on the ricasso as well as the PDL maker's mark on the reverse ricasso. I haven't had any luck finding more information on this, but maybe somebody here will know more. Pommel markings on mine are from top to bottom "1785", "FD", and the crown over "R" mark.
Best regards,
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