These artworks are no longer in public places, at least as far as we know. In some cases they still exist, but have been removed to private spaces.
Musical FountainTan Teng Kee
first placed in front of Plaza Singapura, at its launch. Later moved to Marina Bay, later destroyed.
Athletes in ActionJoseph McNally
Currently not publically accessible, in the HDB offices
Fertile CrescentRamon Orlina
formerly near National Stadium, facing Kallang Basin
Wings of VictoryRamon Orlina
“one day it magically disappeared” in the words of the artist
Temu-sekChong Fah Cheong
relocated from Somerset MRT in 2008 to the SMRT Sports and Recreation Club in Bishan
Surprising SingaporeLeo Hee Tong
Built outside the Orchard MRT station, now the site of Ion Orchard
BreakthroughChern Lian Shan
once infront of the NTUC HQ on Bras Basah Rd
RainbowChern Lian Shan
Removed from its location near One George St. Presumably destroyed.
The ExplorerNg Eng Teng
first placed in front of the Singapore Art Museum, later moved to a side garden. Has turned up at the Singapore Science Centre (2022), but that is meant to be renovated soon, so not sure how long it will be there…
removed in the 2015 (?) renovation of the Asian Civilisations Museum that saw the introduction of the Shipwreck Gallery