Interesting question. Obviously a collector wants model and serial numbers present and completely original on the case. I presume this has quite a big effect when talking about quality pieces in Mint to NOS condition especially because there's more money involved.

We all know that Heuer had not a very structural way of keeping records of there serial numbers and also not the way they dedicated the serials to certain models.

I do have four things that come to my mind when talking about serial and model numbers on our beloved vintage Heuer watches.

1.There are a lot of manual wind Monaco's which don't have the Heuer logo and Tool.33 inscription on their casebacks. I had an 73633B in very good conditions myself some time ago.

Are we 100% sure these are all "put-together" Monaco's or is there a chance also Heuer used these casebacks themselves?? I believe these casebacks were intentially made for selling to other watchbrands like we've seen "Bucherer" and "Villard"...but I also believe Heuer used some of these themselves.

2.There are (were) also 11630 Autavia cases in 100% NOS condition without any signs of model or serial numbers. What about these? Was it some kind of production batch of Autavia cases that couldn't meet the Heuer standards (however I really don't believe this as cases I've seen were really perfect). Where they intended to sell to other watchbrands to construct PMH. Was it still old stock when Heuer was taken over by TAG and cases came on the market at that time? Here's such a perfect 11630 Autavia case without serial/model number.

3.How do we feel about the serial and modelnumbers are re-engraved newly because some serious restoration work was done on the watchcase? But knowing the numbers are 100% correct ofcourse as this can be proven by pictures from before the restoration? Ofcourse we're not having the discussion here about the compairison in value between a restored watch and a 100% complete NOS example...just talking about model/serial numbers with respect to authenticity.

4.What do most of us collectors think about the Caliber 15 Monaco's?? Should these Monaco's all have the 1533 modelnumber stamped into the case? Does it affect the value when a caliber 15 Monaco has the 1133 reference stamped on the case? Well, my personal opinion is that a caliber 15 Monaco can perfectly be housed in an 1133 case originally by Heuer. I've seen many and many of these 1533 Monaco's over the past 6 years and I must admit that most of them were housed in an 1133 case. I think and feel this is completely OK. Anyone else thought about this issue??

Just some quick thoughts, so let the discussion roll on ;-)

Cheers,
Abel.