Advanced Dungeons And Dragons | Dungeon Masters Guide

The Official Advanced Dungeons & Dragons Dungeon Masters Guide. These are my original core books from 1979. I can't believe that I was 14 when I bought this. 

This copy shows considerable wear, but the binding and pages are firm. I thought that there might be notes in margins but a cursory flip through didn't reveal any.  ID tags on the inside cover page

SBS10