Sometime between 1930 and 1959 when mainmast was removed, the foremast was shortened, a new signal mast was fitted behind the bridge and funnels were heightened. 4 years later she became Lakonia for Greek Line and the same year met Davey Jones
They were indeed sister ships, (JVO was Yard no.194, MVSA was Yard no. 195.) Launched, completed, and entered service just a few months apart in 1930. MVSA is not as well-known today since she was lost in 1943.
By the way, the ship in the above photo is indeed MARNIX VAN ST. ALDEGONDE; she has the large windows across her bridge front. On sister ship JVO those were portholes.