Hello to all, long time lurker first time poster... I recently picked up the Seamaster mentioned in the title, 36.6m jumbo case, gold cap, hippocampus case back from around 1958. While it has been serviced and runs to within 4 seconds, the inside of the crystal around 6 is damaged and the crown is looking a bit tired due to some of the gold plating coming off. Given it is an uncommon reference I haven't been able to determine what crystal/crown I would want in order to replace (I can live with the crown, but the crystal bugs me more than I thought it would). Digging around using these dual reference numbers.. and given both references appear to take these part numbers; my guess is the crown would be 42023, and the crystal might be an equivalent to PX5005. I don't know whether these deductions make sense or if a member here has more concrete knowledge?