1967 rolex 5513 buying advice

[Jro40]

Hello everyone,

I'm in the market for a meters first 5513. I stumbled upon a late 1967 Rolex 5513 with a 2002xxx serial. I was told the dial is untouched and the bezel is a fat font MK3 and also original and the case unpolished. It also has some sort of engraving on the back. Could it be some sort of military or official issue or a personal engraving? Price is around 16k without bracelet
Any help or input is appreciated.

Thank you