Did the 6306 come with 2 different crowns?

I can't be sure as I've narrow experience with 6306/6309s, but my 6306 has a 'big spline' crown, but my 6309 has a 'small spine' crown. Perhaps that's the two part numbers. As far as I know, earlier examples had a crown with the big spline and this was later replaced with the small spline model. Spline referring to how chunky the grooves on the crown are.

tritto said:

I can't be sure as I've narrow experience with 6306/6309s, but my 6306 has a 'big spline' crown, but my 6309 has a 'small spine' crown. Perhaps that's the two part numbers. As far as I know, earlier examples had a crown with the big spline and this was later replaced with the small spline model. Spline referring to how chunky the grooves on the crown are.

Click to expand...

If that's the case, I find it quite interesting that Seiko replaced it on the 6306 and used the updated one on the 6309, but continued using the old one into the 80's on at least one pulsar model. This is one of the reasons I'm curious about the origins of my new pulsar. Ties to Seiko diver heritage are quite prevelant, but since it doesn't have the Seiko name, there is very little info available.

As always, there are no definites with Seiko.

Edit: while only one # shows up for the 704x, both show up for the 729x and 7548 variations, so Seiko did apparently continue using both. Soon I'll have the Pulsar in hand, so hopefully I'll be able to identify differences in a side by side comparison.