To me the quest for information and building the mental database is a big part of the lure. Being over there and finding so many of these, I would be tempted to look into and ask around about marble companies in your part of the world. Not everything is known about them. Winnie was a marble fanatic (RIP) from your part of the world who was a valuable resource, went out and did the digging and came up with provenance about the wirepulls, attributing them to Veilligglas, and some other European marble info. That work is still unfinished IMO, as we don't know where the majority of your marbles came from. The reason nobody can tell you who made them is we don't know. If you can find out what company made them and where it was, they will suddenly have more collectability simply because they can be attributed to something/someone/somewhere. Right now these types are in people's mystery boxes with no info. I said on another forum that I thought they were foreign to the US and somewhat resembled Akros and Vitros but that they were off enough that I had to go with foreign. Never said they were "fake".