In 1954, he joined the main board of the NPS of which he for some time also was the secretary.
[2] At the 1955 Surinamese general election the NPS lost almost all the seats in parliament and also Sof was not reelected.
He was civil servant in Moengo when he could return in 1958 to the Estates of Suriname.
This time he would stay 11 years member of parliament and he was also the NPS-faction leader.
[3] At the general election in 1969 Sof was unsuccessfully the NPS candidate for the district Upper-Marowijne.