It is my pleasure to share the piece, thank you for the kind comments :)
The history goes something like this (I'll just do a short one from the 60s onwards) in the early days there were many producers that competed in Observatory trials (Zenith, Peseux etc) , there were many more Observatories that did testing (Geneva, Kew, Besancon Observatories just to name a few).
Movements from these brands were specifically made for testing at these Observatories (like making an F1 car for the track). Tests from these Observatories ranged from 30 days to 50 days.
GP had their own movement and one of the first (if not the first) research and design company and out came the 32A movement, it was improved on an earlier model, in essence it is like having a factory tuned vehicle compete with the F1s. The GP 32A is also the first movement that beat at 36000 bph while at the time in 1966, 67 etc. other watche manufacturers had watches that beat at far less.
The test at Neuchatel Observatory (if my memory serves correct :S) comprises of 45 days of testing (COSC is 15 days), 5 positions, 2 temperatures, and 10 series of 4-5 days per series. If the movement can pass the test, it has the right to have "Observatory Chronometer" on it's dial as the designation.
The average deviation per day had to be within +/- 0.75 Seconds for Neuchatel, while as we know COSC is -4/+6
Thermal deviation had to be +/- 0.20 sec per day for Neuchatel, COSC is +/- 0.60 sec. per day
670 GP 32A movements passed the trials and were sold to the public.
As for the history,
Initially in 1966 Girard Perregaux submited 662 (a trend it seems :D) GP 32A movements to what is now COSC and they received "esspecially good results" , out of these 662, GP submited 40 for further testing at Neuchatel, they passed and were given the title "Observatory Chronometer"
In my understanding in 1967, 662 GP 32A movements were completed in the factory in October and imediatley submited and passed the trials at Neuchatel, they accounted for a bit more than 70% of all movements that passed that year, earning GP a prize from the Neuchatel Observatory, my watch is one of these 662 :)
As for my watch,
The previous owner purchased it and it came like this,
The GP restoration dept. has an excellent team and the main curator of the museum (name removed upon his request) identified an incorrect dial on this piece (if you can notice it doesn't line up that well) and as you can see above it is listed as "Chronometer HF" which indicates that the movement passed COSC but not Neuchatel, GP's curator found that it was a completley incorrect dial and the restoration team made a custom dial from a original base plate as well added the correct "Observatory Chronometer" from an uncommon naming plate.
The restoration resulted in this:
Fortunatley there is now a nice display back on this piece (installed by previous owner, a collector friend of mine :) and his photo borrowed) , the movement is fairly plain compared to other movements, but I love the features and look of it regardless,
I feel very fortunate to have picked up this piece, I call it the "Phoenix" since it rose from the ashes and will have many, many more years of wrist time to come in the future :)
Thank you all for your comments :)