Vintage Solar 21 Man's Watch 21 Jewels - Ticks!

This watch does wind and set. It will tick. It keeps time to about 20-30 sec a day. I don't know the service history - it may need a clean or oil before long. The top of the watch looks gold plated and shows a bit of wear and tarnish. The back is either base metal or stainless steel and screws on/off.
The watch is about 34.66mm in diameter. The lugs around 17.88mm.