The Ender Core for Ender IO goes back to 1.7.10 (Ender IO otherwise for 1.5.2 is still accessible and Ender IO didn't need a core/library/api mod during 1.5.2 or 1.6.4 only in 1.7.10 onwards) but I assume you aren't after that mod.
Otherwise I don't really know a lot about 1.5.2 mods or where to search for any to an archive.org extent of things without knowing more about it to narrow down the search and avoid searching for the other well known one that usually yields results now. So you'd have to explain what you mean by the Ender Core mod for 1.5.2 your talking about.
The Curseforge page only goes back to 1.7.10.
"We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far."
The Ender Core for Ender IO goes back to 1.7.10 (Ender IO otherwise for 1.5.2 is still accessible and Ender IO didn't need a core/library/api mod during 1.5.2 or 1.6.4 only in 1.7.10 onwards) but I assume you aren't after that mod.
Otherwise I don't really know a lot about 1.5.2 mods or where to search for any to an archive.org extent of things without knowing more about it to narrow down the search and avoid searching for the other well known one that usually yields results now. So you'd have to explain what you mean by the Ender Core mod for 1.5.2 your talking about.
Niche Community Content Finder, Youtuber, Modpack/Map Maker, Duck
Forum Thread Maintainer for APortingCore, Liteloader Download HUB, Asphodel Meadows, Fabric Project, Legacy Fabric/Cursed Fabric, Power API, Rift/Fabric/Forge 1.13 to 1.17.
Wikis I Maintain: https://modwiki.miraheze.org/wiki/User:SuntannedDuck2