Help Identifying, Rolex Date (1500?)

[iLLGT2]

Hey guy's, big Rolex guy but much more so modern... Have this older Rolex Oyster Date from my grandfather, and need some help identifying it's year/ref (I know without serial ,ust an approximate) or I can take the bracelet off..

Looks to be from research a 15000, since it has the hack feature and quick set date function. It's all original, never been serviced, etc.. I have checked out pic's of other 15000's however and the lume dots behind the indices seem to be farther spaced than others seen? I'm sure there are just endless variations however from year to year, watch to watch.

Thanks guy, I can take more pic's to further explore

Martin