Well in fact these watches are solid gold Respectively 14k (Certina), 18k (Zodiac) 14k (Roamer), 18k (Certina)They are so adorable! There are so many to collect and if one keeps to plated watches there are some nice ones in white gold and also solid silver from the early 70s.
Unfortunately I don't have any silver or white gold plated Certina yet. But I have a half of solid white gold
Don't know why somebody dumped only the top half to scrap. But someday I may need the movement so here it is, hidden in my collection.
Also I have one Certina that is 40 micron yellow gold plated, which was new to me. I only saw 20 mic plating on Certinas before. Sorry I don't have a stamp photo, it's between the lugs.