So uh, even though it looks like it works in 1.7.10, it has landmines. This is because getAABBPool and getWorldVec3Pool no longer exist. So various items would actually crash the game when being used!
Here's the good news: I sat down and quickly converted the current state of the repository to be 1.7.10 compatible. Everything works properly.
Here's the bad news: I had to munge some things to make it compile properly... this included hucking the entire libsandstone dependency source into the repo, along with the JToml source code. And I had to remove the modtracker code, because Hashing.md5().hashString(data).toString() is no longer valid (hashString now needs CharSequence, Charset as params instead of String) and I didn't feel like patching it.
You can grab the code from my fork. Because of some of the other changes I had to make to get it to compile and work, I didn't make a PR.

Thanks for the continued work on the mod, guys!

Hey, thanks!

Yeah, the Gradle stuff needs worked out. Did libsandstone hold up okay on 1.7.10?
Also, I'll see if I can't find an updated ModStats.

libsandstone as-is compiled fine iirc, but I've never had luck getting Reliquary to build without it, nor get Reliquary to RUN with libsandstone as a separate thing...

Ok, I pushed the update to 1.7.10. The Gradle files are still probably borked, I need to learn Gradle and what I'm doing wrong.