I'm the one who mentioned Anacortes, in connection with the first one. Because I remember an Anacortes with a transparent yellow base. So, no not about a horseshoe pattern. When I said "third guess", it was my third guess for the first marble.
If #3 is Vitro, then I think it would be earlier than Anacortes. Anacortes is 1980's to early 1990's. I'm not sold on Vitro, but if it is Vitro, then I think earlier than that.