I recently acquired two 1970 era Seiko wristwatches in thrifting expeditions. The first was a lovely and elegant Sportsmatic. I wiped it off and have been wearing it for months now. It loses one minute daily, which I can live with. I may crack open the case and adjust it soon however.
The second watch I found last week – a square blue faced gem in a man-sized stainless steel case. I polished the crystal with Brasso, which did an amazing job of removing most every little scratch. It needed a strap though, since the original steel band had been made so small it didn’t fit my man-sized wrist. I then proudly strapped the watch on, only to discover that the second hand sometimes jammed against the minute hand. I would have to open the watch now, but I didn’t know how, since it was not like any watch I’d ever seen. It has two spring clips, which are between the lugs and only visible when the strap is removed. To remove the watch from the case, one pushes in these springs and pries out the case. The case-back is a steel clam-shell affair on which the crystal sits, gasketed to the rim. Once the case is opened the entire top part comes away leaving the watch with the crystal loose on top. I cleaned up the usual gunk and lifted off the crystal to access the hands. With a tiny bit of adjusting I got the second hand to clear the minute hand and assembled the watch. To get it to snap back together I inserted one clip first, turned the watch face down and pressed on the case until the second spring snapped into place. Once you know how, it’s dead simple and very ingenious.
Both watches have a similar auto wind function where the stem only sets the time but does not wind the mainspring. Winding is done by wearing the watch. The stems are made to fit well into the watch cases and thus do not protrude and catch on things the way most watch stems do. I don’t think these were expensive watches, so I admire how well they have lasted, both of them around 40 years old and running quite well.