Are the letters legible?

I don’t have a lot of Mettlachs, but I did find one K and one boxy looking mark which I can’t relate to character(s). I’m not aware if this observation has ever been made before.

I’ve noticed those marks and have always thought they were left by the pewterer to mark his work. 1/2L tapestries and other 1/2L etched pieces on my shelves have the following letters on the underside of the strap: A, K, C. Each mark appears to have been from a stamp in the leather molding strapping, leaving an embossed letter.
One stein i owned had a K that looked as if it was carved in the leather strap with a knife in three short incisions.