This came in a box of Swedish glass, sourced in Denmark, quite some years ago, and had been languishing in storage until a recent excavation of the attic.
Press-moulded, very heavy bright glass, oval in shape, with very pronounced ribs to the exterior that run under the bowl and form the base. The ribs are slightly offset from the longest length of the oval, meaning the space between them compresses and skews as they go around the bowl - it's very pleasing, visually. There appears to be a degree of polished chamfering to the inner edge of the bowl, although this could just be very neat pressing.
I had assumed Czech, but my small post-war Czech glass library and copious-but-scattershot online searches revealed nothing very similar. Ditto for the slim possibility that it was Swedish - it does have a vague Lars Hellsten-ness about it.
Any help appreciated.