The crown is just under 6mm (5.90mm), with the Saturn logo and no cross-hatching. This is for the early turtle-cased version with no external bezel that are "moderately" common. The later Dive(r) 600s have an external bezel, Saturn logo, cross-hatching and clock in at 5.4mm.
I watch ebay, chrono24 and post on this list as you have done. I was looking for a 5.4mm cross-hatched crown for a long time. Finally found one on Italian ebay and managed to persuad the gentleman to ship out of country.