255563 is the ETA movement reference.
237 you guessed right.
4978 is the case reference.

 

Thanks for the reply but no serial number is my concern. The ETA movement is definitely authentic. It is hard to believe longines made such a hi-end watch without a serial number especially since 6 similar VHPs, on ebay, all have serial numbers on the outside of the case back. I'm trying be sure mine is not a fake>

 

Have you checked the case at the end links? Rolex and others do it.

 

How's the dial ?

 

The dial looks very good. The whole watch looks like it had very little wrist time.

 

Thanks for the reply.I looked there and found nothing.

 

https://www.longines.com/certificate-of-authenticity

I would contact them and send them the photos. The email "extract from the archives" is free of charge and I have done that with both my Longines to get their production and sell to retailer time as I wanted to know exactly how old they were when I bought them.

I am sure they can help you with the watch when you ask them nicely.

To me this watch is very cool and has an incredible vintage vibe, plus the titanium is amazing. The serial number must be somewhere....it certainly looks very legit to me.

Cheers.

EDIT: Maybe this is a demo watch or a prototype? Or maybe it got a replacement case back - without the serial number?

 

Well the watch arrived and it does have an 8 digit serial number. Sorry for all the questions but the seller told there was no serial number.