Hi Geross - not sure of the model ref, but....
By: nomadgiles : March 20th, 2020-02:16
... it runs a cal GP440-282 (based on AS1920) at 360000 and was the last of the GP high beats circa mid 70โs - as the little observatory picture provides testiment to the chronometer HFโs that went before. Case is approx 38mm sq, height 14mm and dial 34mm...