Bulova International, maybe?
CASE: width 37,5 mm; lug to lug 41 mm
What might be a close matcg to "C" watch in this advert, but no model name mentioned.
This advert shows what I think is the same watch as the Bulova Calendial. Advert is dated December 1973.
Can you confirm if the case is yellow? It appears to be stainless, but the back references gold electroplate. Maybe the gold is worn off.
Watch is a match to the Calendial "B"
In reply to Can you confirm if the case… by Andersok
A caixa deste Bulova Calendário "B" de 1973 é amarela e está num razoável estado, assim como todo o conjunto. Andersoque, muito agradeço pelas suas pesquisas e informações sempre muito importantes e bem vindas.
1973 Bulova Calendial "B" is a good match.
In reply to 1973 Bulova Calendial "B" is… by JimDon5822
Muito agradeço o seu comentário confirmando Bulova Calendar "B" de 1973.