The plastic brake was introduced in 72/3.
Thank you. Can you actually show me any watch in the wild for reference?
This is why I like this forum healthy debate on a watch
No I can't, but there would be no point if you are relying on Chuck Maddox articles for your speedmaster knowledge.
I had understood this the other way round, which seemed ok for me, since I thought that the"plastic" brake wasn't used before the late 70s and with movement serials up from 39 m.
But would you expect a 31m to have a plastic brake?
I was trying to allude to that as there are now a few “-71’s” with extracts that show -74 production and have -74 case backs.
i still think these where sea monster car backs that got sent back and swapped. But who knows.
MWO says Delrin brake from serial 32.849.xxx references 145.022-69 and -71 towards the end of 1971 production.
Paradoxically models made in 1975 i.e 145.022-74 are fitted with the steel brake but having serial numbers below 32.85x.xxx.
They say that these movements were manufactured several years before being installed in the final watch.
