For example, check out the 1964 Sea Raven. It was produced for two years and is unique from the other sea-somethings because it has a diamond-edged crystal.
The Sea Raven comes in a one-piece 10K RGP case with an integrated stainless steel back. Tucked behind the silver dial is a 17 jewel Swiss-made 686 movement.
I recently purchased a Sea Raven project watch from a fellow collector. The crystal was very scratched up and the dial has seen better days but it's a unique model and rarely comes up for sale. It's definitely worth restoring.
Although the watch runs, a trip to the timer reveals that it's not running very well - 6 minutes fast per day is way too fast... even for a "vintage watch" and the beat error isn't too good either. I think plus or minus 1 minute per day is within reason - although plus or minus 30 seconds or better isn't unrealistic either.
The stainless steel back shows signs of someone trying to open the case from the rear - but this watch opens through the crystal.
With the faceted crystal out of the way you can see the dial has a sort of haze over it. A section of the N in Hamilton is missing, as is a tiny section of the seconds register. So I'm going to leave this dial as-is and not try to clean it - there's a significant probability that any attempt to clean it would remove the printing all together.
It will look a lot better when it's under a new crystal.
The 686 movement is in decent shape but definitely needs a thorough cleaning.
The dial-side of the main plate is also fairly dirty - so this watch has clearly not been serviced in quite some time.
Finding this style of crystal is pretty tricky but it's a requirement. A non-faceted crystal would change the watch's overall appearance. Not a lot of places carry this style and GS crystals are not the right profile (they stand way too tall). Stella DEC crystals are the best alternative I have found. This watch takes a 30.6mm diameter crystal.
The movement is completely disassembled, cleaned and dried before being reassembled with fresh oil.
The newly reassembled movement is ticking away nicely but you never know how well it's running until it goes onto the timer.
The 686 is a nice movement and it allows you to adjust both the beat rate and the beat error so I was able to fine tune the movement to a very acceptable performance.
And here's the finished project watch, running well and outfitted with a fresh crystal. My camera is merciless and shows every flaw in the dial. It looks way better in person and the gold accents along with the facets in the crystal really make this Sea Raven sparkle!