OK, so after spending almost 3 hours searching, I managed to find 1868_v1207.zip. I've attached it here to save people this headache in the future.
1317.zip is included on Page 2 here so I won't attach it to this post.
I followed the steps in my last post with the exception of installing DirectX 8.1.
The extra setup I did was:
- From the combined files of 1317 and 1207, run the SETUP.EXE package
- The computer will reboot and on start, ask you to insert the disk for the drivers. Just navigate to the place you stored the driver files and click OK
- Drivers will install and system will reboot
- That's it, done
Now, I am not sure that it is perfect. I cannot get Dinopark Tycoon to run with any kind of sound or music (and in true DOS, the game doesn't even start properly - never has on this system), but Duke Nukem 3D's audio works just fine.
Doom's audio is also fine with both the Doom95 sourceport and the PRBoom sourceport.
At this point, I don't need a higher version of DirectX than what I'm already using (which I think is DirectX 6.0) so I haven't tried with DirectX 8.1 and probably won't unless I absolutely have to.
Thank you squ1rrel for your detective work on this. Hopefully this thread will help others in the future.
If so, hello future people - hopefully this works for you, too!