The marking attached is from a 2019 Romanian RPK AES-10B I was thinking about purchasing. I wanted to know if you thought it to be a proof mark, inspection mark, graffiti, or a slip of the hand ? Maybe an ex military receiver that was sanitized and reused ? I have looked online and see some WASR rifles with a M in about the same location. I am not sure what the M means, but at least it is an intelligible marking. I also saw an X in a circle which is close to the JPEG I attached here. I attached that JPEG and circled the faint X in Blue. The marking I am curious about is circled in red in the other JPEG. Thank you for taking a look.
