Hi Paul,
If you had not given the dimensions I would have said straightaway: bulbvase. This model begins to show up in the bulb catalogues of around 1910 and I have them myself. Always bought in England and also the bulb catalogue is English.
The size however is very small for a hyacinth (when the roots start to grow they have nowhere to go), and for a crocus I can imagine the neck is too wide and the bulb will fall through.
The alternative is that it might be a posy vase. When I started to collect bulb vases I ended up with quite a few of those, till the bulb farmers set me straight.
Your glass question I cannot answer apart from the fact that mine are with dimples, hobnail, plain, optic etc.
Hope all this is of any use.
Patricia
P.S. Afterthought: Dartington made something similar and they were candleholders!