Err...Hello Heuer OTD buddies...this would be O's 1st posting in here...
O is a complete idiot about these Heuer watches...

O is seeking help from those with similar experience in here...
n hoping to find out more about this odd looking case serial nos. which looks like the middle portions of the serial numbers...
"0864" of "1 0864 4" was being crossed out...like deliberately done.(not looking like it was accidentally done)

What purpose would that serve to indicate?
Could it have been intended or used as a test for water proofing of the Compressor snap on backcase cover?
or the case was assigned for an experimental or expeditions...n it was NOT meant for sale sample...Maybe?

Also O needs to understand what is the meaning of the engraved Service Remarks on the inside of its CB cover...
Could it be "Patchet" or "Ratchet" or something to do with a "valve"??

Could it be that the Service markings were done officially recognised by Heuer Service centres...in USA?

Or could it have been done by external source watchmakers...else where?

Serial nos. look like the middle portion of 4 digits were being crossed out:

Service Markings:

Thanks very much in advance for the feedbacks,

Best regards
Orchi.