There was an Ofmega/Avocet sealed bottom bracket that looked just like that. It would be my first guess. Ofmegas was known to rebrand their components for others. Maybe OMAS or EDCO or something else though. The dual adjusting cup was a common configuration for sealed BB around 1980. Before too long everyone just copied the Phil Wood cartridge concept.

On second glance I'm going to go with OMAS. The cup covers look more correct. Avocet cups left the sealed cartridges partly exposed, and it's possible Ofmega wasn't the OEM for those BB at all.