Vintage Longines Divers - Bad Luck Streak Continues

A while ago, I got a Longines 8484 diver with hummer movement:



Looks nice, but half of the bezel was stripped of teeth underneath and was very loose. The crown gasket melted onto the winding tube. The bracelet and end links were atrociously polished and bent beyond recognition. And of course, the date would not advance. I got lucky and the seller refunded my money.

Thinking it might prove a better piece, I recently got this 7970-3:



Looks nice, yes?

Oh wait, move the watch a little in the light and the dial's condition becomes apparent:



I knew the bezel was cosmetically rough. No problem. The case is in decent, perhaps good condition.



The movement, however, appears to have bits of oxidation all over. Or else that is graphite lubricant making a mess.



Something got messy on the caseback and will not come off. Moisture damage?



All said, however, I like the watch. The size and shape suit me. I am worried about the movement, though. It seems to keep time well enough, but the sweep seconds hand moves erratically, especially between 12 and 6.

Would those of you familiar with the high-beat 431 movement mind taking a moment to watch this video to see it anything seems amiss?

http://s608.photobucket.com/user/camuswasnoexistentialist/library/Longines7970

I just don't seem to win when it comes to Longines divers! :-(

Wrong video URL!

http://s608.photobucket.com/user/ca...ia/Longines7970/MVI_5902_zps7ecaa681.mp4.html

Many thanks, Al. That helps assuage a few of my fears.

I noticed yesterday that the winding rotor weight was loose on its carrier. This is visible in the movement photos above—the gap between the "Longines" carrier and outer weight. I gently nudged it back in, but once again, it makes me wonder if this is a keeper.

Hi, I ended buying this watch after danomar returned it.

The dial is quite crackeled, but I am OK with it.

The movement, on the other hand, is quite beaten up. I took it to my watchmaker, who cleaned it (he told me it was quite dirty) and the recommended me not to wind it up manually, because some wheel (??) was worn out. The second hand jitters like crazy...

Out to out, I don't regret having bought the watch, but now that it is mine, I wouldn't mind having paid something more for a better kept piece.
I suppose that's the way with vintage watches. From time to time you hit the jackpot, but usually the best you can say is that you get what you paid for...