Looking at this 1969 Speedmaster DON. What's up with this dial coming away from the side of the watch?
Ah I see, easy to replace? It has DON bezel. Otherwise may class as 'running'.. not good, condition..
Looking at the edge of the dial, I would say somebody removed the tension ring to keep it from rubbing the dial further. You probably should just replace the crystal to be safe. Should be about $50-$75.
Watch is owned by @KRLYUZH. Who's an absolute nice gentleman. And a member of this forum. I'm sure he'll answer all your questions accordingly.
He is also banned for ripping off a forum member so no longer frequents here to post. Please don't go in to it all over again as the thread will get locked (which is rare)