I thought I had a match for the OP in my Vitro pile, but after rooting around these are all I could come up with (search continues)
Bottom right are obviously Pelt
Carry on!
Looks like one of those foreign marbles referred to as pincers (or pinchers, don't recall). Anyhow, machine made probably 50-70 years ago judging by the lots I've found them in previously
Hangathered for sure, but unless the pontil is ground/faceted and the marble is a lot more "round" than it looks in the pics I'd say No to Greiner for the OP