>>536835260
There's a ton of builds, from the time it was supposed to be a futuristic shooter with robots and Aztec temples to the late pre-release versions of SoC. There's a full list with download links for most of them on the russian wiki.
https://stalker.fandom.com/ru/wiki/%D0%A5%D1%80%D0%BE%D0%BD%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B8%D0%B9_%D1%81%D0%BF%D0%B8%D1%81%D0%BE%D0%BA_%D1%81%D0%B1%D0%BE%D1%80%D0%BE%D0%BA
If you're looking specifically for the original Oblivion Lost, before the setting was changed to the Zone and stalkers, Build 1098 is supposed to be the latest known as well as the most complete one before the concept change.
https://stalker.fandom.com/ru/wiki/Build_1098