What I'm actually doing is compiling the evolution of the wood bow to the modern composite. Since Frank Eicholtz is one of the main players from his work with fiberglass backings first, then fiberglass facings, of necessity I have collected a great deal of information on his activities. I'm at 1952 which is basically the year fiberglass took complete control of backings and facings.
Fiberglass is also a plastic. If the facing is truly plastic, it is most likely the plastic Lamicoid which was typically white and the bow would be 1952 or earlier. Eicholtz began advertising Glasface, a pure white fiberglas facing in late 1952. The first ad with Glasface I have is dated September, 1952.
I've not seen any Eicholtz ad or article mention any bow with a "model name," which is what "Neptune" is, to this point. Other bowyers have for some time.
I suspect this bow older than 1952 and Fred Anderson knew Frank Eicholtz and his bows first hand, so he likely could give a good accounting of it. Tom Baldwin, Wade Phillips or other "bow collectors" probably are familiar with it.
Best I have.