Michael, I too would look towards "Novy Bor." I think these were made at at the Crystalex complex, which I think may sometimes have a Borocrystal label.... like other pieces you have recently posted.... Czech glass history can be very complicated... none of us knows everything... one of the joys of learning.... hopefully Jindrich can add a little more if he sees the post.... another nice piece for your collection,
Robert (bOBA)