[martback]

I spent some time looking for a nice set of early 6139-600X watches and there is certainly a lot of them out there and also a fair number of mix-and-match with parts from lots of individual watches. This got me thinking a bit about the dating clues for these watches. So far I have (and these are just broad guesses without having searched the whole internet) Feel free to correct as this could provide some guidance for others:

Two piece second hand: Good dating evidence, not much overlap, switch Q1-Q2 1970.
Notched case: Good dating evidence, not much overlap, switch Q2-Q4 1970.
Flat hour and minute hands:Good dating evidence, not much overlap, switch Q1-Q2 1970.
17/21j 6139A caliber: Not dating evidence, complete overlap.
6139A/6139B caliber: Fairly good dating evidence, some overlap, switch
Proof/resist: Fairly uncertain dating evidence, overlap large between geographical markets, resist starts Q3 1969, proof ends ?.

This is what I ended up with: a yellow dial JDM 6000 from June 1969 and a blue dial 6009 from November 1969.

- martin

 

[cartshed]

Great pair & they're both from my birth year! Particularly like the gold proof dial. I'm quite envious of your latest purchases as I've being looking for one of these for quite a while but even slightly rough ones seem to be fetching very strong money in the UK.


Enjoy the hell out of 'em :clap:

 

[SeikoPsycho2]

I currently have two original Blue dial Resist 6139-6009's from March of 1970 with notched cases and two piece second hands. Serial numbers show them to be 42 numbers apart. Here is one of them.

There are also four different case backs:
Proof horse shoe from 69' to Feb 70' at which time I also believe Proof dials ended.
Resist horse shoe to about April or May 70'
Resistant horse shoe to 79'
Resistant plain from 76'- up.
These are approximate dates as I would have to check to narrow them down closer then that.

Two piece second hands were only used on 6139A movements from what I understand.

Tom