Hello Breitling experts!
I've posted this on Watchuseek as well, but I thought it would be a good idea to post here as well

Newbie seeking advice, so be gentle.

I'm new to the watch collection scene, but I am hoping to kick off my collection with a Breitling Navitimer Pluton 3100, as I am still studying.
I have an upportunity to pick up a Navitimer Pluton 3100 without strap/bracelet from a local private seller for just under $600. Now, the ad is without pictures of the watch and generally lack info on the watch, but as the seller is locally based, my plan was just to pay him a visit.
As I am new to this scene, I'm not too sure what I should look for when inspecting the watch.
- From what I've read, this isn't a watch that has been subject to counterfeiting, but can this be confirmed?
- Also, I've read that the movements used in these watches have all went out of production - should I be concerned about that?
- Of course, the first thing to check is if the watch is in running order, but is it necessary to remove the back piece for inspection?
- If the watch isn't running, and the seller says it is caused by a dead battery, should I stay away from buying it?
Any other thoughts on the watch (and the price of it) are very, very welcome.

Thanks in advance!
Best regards
Rasmus, Denmark