This one turned into more of a research project than a restoration for a while.

The watch that landed on my bench in pieces was the Seikomatic Lady, a non-runner, and honestly not in great shape. The dial had seen better decades, and there was nothing about it that told me what I was actually dealing with once I got the case open. I figured I’d pop it open, have a look, and get a rough sense of what needed doing. That’s not quite how it went.

Opening it up

This might be the dirtiest movement I’ve come across so far. Not rusty, oddly enough — I was half expecting corrosion given the state of things, but there wasn’t any. Instead there was this strange fibrous material threaded through the movement, almost like wool or a bit of spider web, wrapped around several of the components. It had built up enough that the escape wheel couldn’t turn properly. At one point I genuinely wondered where this watch had spent the last few decades, because that’s not the kind of contamination I’d expect from a drawer.

Figuring out what it actually was

The movement itself was only marked “Seikosha 21 Jewels” — no calibre number in sight. I went through the usual Seiko references and caseback databases and came up empty. Not helped by the fact that the movement has an unusual tonneau/diamond shape rather than the round layout I’m used to seeing, so even matching it visually was harder than normal.

There was a “94” stamped somewhere on it, plus some case markings — serial 270050, an internal case number of 4500301, and “JAPAN B” — but none of it pointed anywhere conclusive on its own.

I ended up going down a bit of a rabbit hole before I remembered I’d actually asked about this exact watch in a Facebook watch group a while back. That old thread was the missing piece. Turns out it’s a Seiko Calibre 2101, one of Seiko’s earliest automatic movements made specifically for ladies’ watches, according to 17 Jewels. That explained why I was striking out everywhere — it’s just old enough and obscure enough that it hasn’t been documented the way later Seiko calibres have.

Working without a manual

Once I knew what it was, I went looking for a service guide, an exploded diagram, anything. Nothing. No factory manual, no parts catalogue, not even a YouTube video of someone servicing this specific movement. With an ETA or a more common Seiko calibre I’d usually have something to reference before I touch a screwdriver to it. Here I had nothing, so I just slowed right down.

I paid close attention to the order things came off, where every spring sat, how the automatic winding mechanism was arranged, and how the bridges related to the train — basically trying to build my own mental diagram as I went, since nobody had done it for me. The good news was that once I got past the grime, nothing looked actually broken. It was just filthy.

Cleaning it up

Given how much was in there, I started with a manual pre-clean using IPA to get the worst of the fibrous mess off before it went anywhere near my cleaning machine. After that it went through my usual setup — parts in a basket, spun through a jar of lighter fluid for the first rinse, then a second jar for the rinse after that, then dried before I started putting things back together.

It’s a pretty basic setup, but it’s worked well for me on the vintage pieces I’ve done so far, and this was no exception. Once everything came out clean, it finally looked like a watch movement again rather than something dug out of storage.

Putting it back together

Reassembly ended up being more straightforward than I expected, given I had zero documentation to lean on. The layout made enough sense once I’d taken it apart carefully that I could work it back together in reverse without too much guessing. Train wheels turned freely, the escapement was clear, and after lubrication it started right up.

That’s still my favourite moment in any restoration — watching something that arrived completely dead start ticking again. No exotic parts, no dramatic repair. It just needed to be properly cleaned, and it came back on its own.

The bit I haven’t solved yet

There’s one thing still bugging me. Once the movement went back into the case, I noticed it sits a bit loose in there — more movement than I’d expect. My first thought was a missing gasket around the crown or stem, but I’m not convinced that alone would explain the whole movement shifting around like that.

My best guess right now is there’s meant to be some kind of retaining ring, a case spacer, or a movement clamp that’s gone missing at some point, maybe during an earlier repair. I haven’t confirmed it though, so I don’t want to call this one finished yet. It’s running, and it’s clean, but it’s not properly secured in the case, and I want to understand why before I move on.

If anyone’s dealt with a Calibre 2101 and knows what’s supposed to be sitting under that movement, I’d genuinely like to hear from you.