An external independent contractor overwrote the snippet/quantity-selector.liquid code with fully custom code (that I do need) but I also need the original code.
I tried looking in the Recent changes dropdown, but even the oldest version there is the custom overwirte.
Is there another way to recover the original code?
Your best bet would be to look at the original version of that file in your theme. But in addition to that, going forward, I’d strongly recommend you use github for version control because if that were in place you’d have a way to roll back.