Help with 1.3 update for Mac

[xxjaz1228]

Hey, hopefully this gets some response in 2019. So, I bought Amnesia many many years ago back when Frictional games still had their own store on their site. I didn't buy it off Steam or Humble or any other online retailer.
I've recently (in the past couple days) had two really great custom stories suddenly crash when loading a new map because I don't have the 1.3 update that they came out with a few years back (I'm just seeing this update now), and I have no idea how I'm supposed to get this update since frictional games no longer has their own store.
I've been looking around online and I can't seem to find a way to get it besides buying the game all over again on one of the different sites, which would be really shitty considering the amount of mods I already have on my current amnesia application and I don't just have twenty bucks to throw down for the exact same game, ya know?
Someone help me out please