Just revisiting this...
There were several companies that were decorating (but not making the glass) in the 1950s, but the black enamel is not that common.
On the Spiderweb vase: if you look closely around the top, close to the rim, you might see 'Celery' acid-etched. If not, it was probably a pickle jar or biscuit barrel – this is the only difference between them, other than the type of lid used that distinguished between the pickle and biscuit.
Hellenic: the long rectangles are the sandwich tray and hors d'ouevres tray (with 3-segments).