Selamat berbuka puasa Manburg. That is a very pristine 6309-7040. What year is yours from? Looks like its all original and in superb condition. Congratulations.
Thanks!

Yes, it's 6309-7040 indeed. It's still young by the way, just reached 30 this month

(it's August 1981).
By the way, not all the parts are from that year. The most obvious would be the band, which I took from my unused watch (this penyu came with an aftermarket rubber strap, which I loathe). The others are the three hands, replacing the original ones which have become a bit too old for good taste. Apart from those, it's original.