I was able to find a first generation 7549 and even though i was I was leaning more towards the 2nd generation golden Tuna with a 7C46 I went for it.
Seiko officially released the first quartz dive watch in 1978. Mine is a very early model, produced in December of 1977 as the 133rd quartz Tuna ever made.
Even though the seller told me it had a recent battery change and gaskets were changed (more on that later), I wanted it checked for sure. Plus it had a spec of dust on the dial and it randomly lost 2min during date change one night.
After multiple suggestions I sent it to John Sachs known as Vette Enthusiast on SCWF.
He did an outstanding job, taking pics along the way and keeping me informed. He only had it just over a week and was able to surpass my expectations.
This model Tuna has a lot of gaskets, and all but one was completely shot. Glad I didn’t take the sellers word for it- I know he didn’t know any better. Heck, I would have said the same thing if I flipped it before getting it serviced.
These Tuna models were extremely overbuilt.
I found out that the 7549 movement is highly favored over the newer 7C46 as it has mostly metal parts and has spare parts readily available. Since the 7C46 is an exclusive Tuna movement and not found in other models, parts are harder to find unless you go through Seiko service center.
The Yobokies sapphire crystal was a great choice as it’s very clear and did not take away from the vintage charm.
Here are some service pics John sent me while he was working on it:
https://imgur.com/a/fIxmC7t
His last set when he finished, you can see he was able to tune the time keeping to .01 sec/day!:
https://imgur.com/a/1vzsP3b
The SCWF thread where he detailed everything :
https://www.thewatchsite.com/threads/wi ... na.350050/
I would not hesitate to send John a Seiko again. I plan to get a 7C46 in the future. When I do it’ll get shipped to him ASAP.
Great guy and highly recommended!
