The Seiko 8T23 is a bit of an oddity. It's the grandfather of todays Kinetic line, but was not a sucess when it was released in the late 1980s because it took a hard three minutes of winding to charge the capacitor. With the invaluable help of @krogerfoot, I managed to find one on Yahoo Japan, but the vendor had replaced the OEM rechargable capacitor with a battery. Seiko doesn't make the capacitors any more, but found a place in France that still had some residual stock. Got it running again this morning -- with a little winding help from the cordless drill....
Cool Just read a bit, does your red light work… https://www.reddit.com/r/Watches/comments/k0wmkk/seiko_seiko_8t23_a_truly_bad_truly_rare_handwound/
It does, which makes it all the more satisfying. The original capacitors had the lug welded to the case and were a weird 2.4v if IIRC. They're impossible to find with the lug and almost impossible without it. There's another good review here.