Some feedback on the results! So I had 2 floppy drives to test, one from trademe and one from acsi. Cleaned both with compressed air and some medical alcohol on the heads. Trademe one ended up being a bust, Abort, retry, fail time after time. A shame because it was pricey! Then went on to the other drive and it read every disk flawless.
I was quite surprised, only had one disk with some bad sectors/unreadable files. The rest were all fine. Quite a testament to the longevity of floppy disks. Most of these dated from the 1980's. Copied everything to 3.5" floppy's then on to a modern PC. Managed to recover all the specialised programs.
Tried running the program on the old PC - "not enough memory". Jumped into the autoexec.bat and config.sys, took one look at the stacks, buffers and files then shut the thing off. Not diving into that again! Last time I had to deal with that I was trying to get my games working in DOS, salvaging every single KB to get enough free memory. So went the DOSbox route, 10min later everything is running fine. So all in all a good result.
Just want to say thank you to all you gentleman for the assistance and advice. Cheers!