Does anybody have any old builds I can download? I have my own little archive dating back to Whales but I have a few massive gaps where I stopped playing a while. I’m missing any 4000 build and any 6000 build though of course if it’s pre 8000 and I don’t have it I’ll take it anyway 
You can compile anything you want.
Like Zhilkin said, git tracks the entire history of the project, so you can rewind to any place you like.
I’m able to bring up the last 30 or so builds on each type, but I didn’t know you can go back further. How do you do that?
I think I see, so if I have git installed on my computer it’s through that I can go back?
Yep. “git tag” will show you a list of tagged versions (it’s fairly long since the Jenkins build numbers were added) but there you’ll see 0.1 through 0.D. You can “git checkout 0.8” to go back to the 0.8 release or whatever, then compile it and away you go.