[guide] How To Legally Install Old Ts Versions Next To Tsc

I have been collecting old boxed versions of TS for a little while when they're cheap on Ebay. I only need to get TS2015 and everything after TS2016.

 

I have a cupboard full of old PC games with their original box, dating back to the late 1990s, sadly, no TS ones.

 

I have a disk copy of TS2014 from when I first started playing and based on this thread (which I'm autistically confused over the technical aspects), I can install a copy of that ver. onto a separate drive, copy my Assets, Contents, and Routes folder, then have a version that still works without the corrupted core updates from yesteryear? I'm stuck on two questions:
1) if I install from the disk, I would be stuck with the 32-bit version that came with the game then?
2) Has anyone confirmed if these older versions are capable of running the higher-hardware DLC, i.e. Searchlight AC4400?

 

I have a backup of RW3 on disk, and I tried to install, but it connected to Steam and installed the latest version. This was a few years ago.