** Now identified** with thanks to Yvon, as one of a pair of Eriksbergs MV, Swedish built cargo/reefer ships for Svenska Lloyd:

VENEZIA IMO 5377991 - https://digitaltmuseum.se/021015770922/lastmotorfartyget-venezia-av-goteborg-i-malmo-den-30-10-1965
or
SICILIA IMO 5326851 - https://digitaltmuseum.se/021015771108/lastmotorfartyget-sicilia-av-goteborg

Circa 1963-1966, the location has previously been positively identified as the port of Leixões, Portugal during the mid 1960's, by Luis Manuel Correia.

Scanned from a poor quality slide in the collection of the late Niels Anker Larsen, former Danish Merchant Navy Radio Officer.