Help appreciated to ID this vintage Speedmaster

Dear all,

About 5 years ago, I was very lucky to put my hands on a Speedmaster, one that has long been in the family, it was my grandpa's.
The Speedmaster has always been on my bucket list, I find its history so fascinating and its aestethics, well, timeless.

I am now engaged to my fiancée and the "tradition" here is for me to buy her a ring (done!), and her to buy me a watch (work in progress!). And already having a Speedmaster, I swear I can't decide which model to go for next...it's like "why would I need anything else ???". 😕

But anyways back on topic. Since I've put my hands on this Speedmaster, I have done a lot of research to try and identify the precise model, but I'm still not sure about it. I do not have any maintenance papers or anything that would justify the model year. I feel like it's a 145.022-69 but I am not really sure...

Also to be clear, I realize how rare and how high the value of my watch probably is, but I am absolutely not willing to sell it. The sentimental value it holds to me is far superior to anything one could offer for it.

Anyways. Like I said, can't ID precisely the model year and asking for your help! I feel like I have a transition model, with attributes from different model years hence my confusion...
So, here are a few pictures, they will speak more than words for the connoisseur eye:

1) The outside

We have here a mix between pre-moon and post-moon. What I notice is a very nice DON (dot over 90), typical from pre-moon models, along with the "è" on Tachymètre. But I also notice that I dont have the classic "stamped" Omega logo, rather a printed one.



The back has the classic Omega SeaHorse, and no mention of the "First watch on the moon".



2) The inside

Luckily, it was time for the Speedmaster to be serviced. So I took her to an authorized repair center, one of the best in my town. And I asked him to send me pictures of the inside, it was the perfect opportunity to take my investigations further, since there is no way I open the box myself.

Here are the pictures he sent me...
First, the inside of the box, which was very surprising (remember: I have a strong feeling that the watch is a 145.022-69), it says 145.012-67 SP. That's not exactly what I was expecting...



Here is a picture of the glass, with the very small Omega logo engraved in the middle...But I dont think this would be of much help to ID the watch...



The caliber...well it's a 861, as expected on a 69 model year...but the serial number "313xxx" is another mystery...from what I saw online, this would match with a MY 1970 ?



Last picture, from the dial (nothing to see here ?):




So that must be all I know about this watch...I hope someone can help me identify its year of production.
Wish you a good day,

C.

congrats on a beautiful memory of your grandfather.
step dial, DON bezel, 31.3m --- 145.022-69 with a swapped caseback.

https://speedmaster101.com/serial-quick-reference-to-78/

Very clean dial, earlier case back, perhaps it's more correct a DNN bezel??
However, congratulations!!!!

The guy with the 145.012-67 must be seeing red today.

Interesting that back in the 1970s or 1980s when the watch could have been serviced for the first time, we don't know the exact date, many watchmakers didn't pay much attention to casebacks or inserts... did they even talk about DON or DNN bezel inserts? The caseback should have been a straight writing, correct? The luminova service hands would have had to have been done at a later service, maybe in the late 90s.

In time, if the OP wishes to, he could restore the watch to it's original condition, might even make a few dollars in the sell of the DON for the DNN. Still a very nice heirloom as Dan S stated.

Hello Everyone,

And thanks for all your quick answers! This comforts me in the idea I had that it would indeed be, a 145.022-69.

@ndgal wow this would be a crazy story!
So if I understand correctly, mine is not supposed to have the DON bezel, but this (and the caseback) would have been mistakenly inverted ?

@Marsimaxam thanks for your feedback, very interesting to be able to find more about the watch history by looking at all its components (I never thought about a later service with the Luminova hands!). I could restore the watch to its original specs but in the other hand this was handed to me this way and this is how my grandpa must have worn it for most his life. I will keep it this way for now!

Wow, this is crazy! I wonder how many of those mistakes happened back then...Was it really this frequent ?
I can't imagine something like this happening nowadays, especially considering how sought after the DON bezels are...
As @Marsimaxam said, the other guy must be quite upset...

So, my watch would be one of the last 145.022-69, and thus one of the first of them to get a DNN bezel if I understand correctly.

That's very interesting, thanks so much for all this information.