Omega Seamaster 300 165.024 transition to screwed crown... or not

I can see there this: an early 70's Swiss catalogue In German. Features Seamaster 300, 120 , Chronostops , Speedmaster Pro & Mens Dynamic.
I think the successor from design point of view was Omega Seamaster 120 166.073 Deep Blue.

I don't think that's a 1970's catalog. The person who uploaded that catalog wrote: "This is a Swiss catalogue, in German. I guess it's from the early 70's / late 60's."

Looking through the catalog, the Chronostop and Dyamic models appear to be circa 1968 models. I would say the catalog is from 1968.

So, as far as I can tell, Omega apparently removed the Seamaster 300 from the 1969 and later catalogs -- even though the 300 was still being assembled as late as autumn 1970 (per the movement serial numbers).

This evidence suggests Omega apparently discontinued the 300 for the 1969 model year, but continued assembling/selling them until stocks were depleted in late 1970.

I do think the Seamaster 120 and Seamaster 200 references that stayed in the catalog and were apparently replacements for the 300 were significant design downgrades vs the 300. It would be interesting to understand why the powers that be at Omega decided to kill off the 300 circa 1969. Was it a poor seller? Were they getting a lot of complaints about water ingress with the original Niad crown so they discontinued the 300?

It has moved from tool/military look to more fancy 70ties watch, more mainstream design I think.
The tool watch purpose has moved to the Ploprof & SM1000 models.
Sure the SD crown was a more bulletproof solution, but I don`t think Naiad was a model killer.
It was in the catalogues for 6-7 years, which is not unusual at all...even today.

Hi. Does anyone happen know the 'O' ring size for the screw down crown on these 165.024 ref. please?? I've looked everywhere and can't find any details.

Thank you