looks very nice overall but have a few unusual places:
1. the space between official certified and sea master is too close and the font of official certified is strange.
2. the omega inside the triangle in the backcase looks strange.
3. I cannot find any 14k gold marks on the case. I used to see marks on the lugs from a few other YG2518.

Please share your thoughts. Very appreciated.

 

Looks like a possible* redial when compared to the vintage database:

 

Case back has the 14K markings. Photos don’t show where markings could be on the backside of the lugs. Looks to have met a polishing wheel or two...

 

here is the backside of the lugs. no mark found

 

Looks like there’s a hallmark on the lower left lug, but after the few meetings with the polishing wheel, it’s hard to make out.

 

thanks for the info. how to identify it is chemically clean? because the marks are dimdim? thanks

 

watch is very attempting but havent pulled the trigger yet.