Great case back 
Cheers John, I like the fact that you could probably use a ring spanner if it got stuckGreat case back![]()
I knew you were going to say that! lol read your convo the other day on case backs. Very interestingGreat case back![]()
Hi39 Jewels and a crown on the back... had a quick google, it's a "precursor to the 1st Generation Automatic Grand Seiko models", for £5 I'd call that a pretty spectacular result!
http://seikoholics.yuku.com/topic/916/Seiko-J13083-the-39j-protoGSAuto
Keep looking, but if you come up empty-handed, maybe consider the 329W04AN, it is used on the J13061, 2, and 4. If 32.9 seems too large, another old crystal is the 327W01AN, used on the J13081. No guarantee that either would fit- I've no direct experience with that model.Talking of crystals, If anyone knows the part number for this model I'd be grateful,
I have nothing in my casing guide for this one and I'm coming up empty on borel's and boley's database.
Thanks for the info Noah, I have a decent vernier so I'll pop the crystal some time this week and compare to those two part numbers, fingers crossed you may have saved me much googling,Keep looking, but if you come up empty-handed, maybe consider the 329W04AN, it is used on the J13061, 2, and 4. If 32.9 seems too large, another old crystal is the 327W01AN, used on the J13081. No guarantee that either would fit- I've no direct experience with that model.