We paid the telco company to come in and identify the lines, some were standard phone lines, some were killostream and framestream lines and isdn30e lines. They also ran a 40 pair cable from there to the comms room. Then I had to move the lines over from the old stuff to the new cables which then used the cat5 cabling for the phone lines. I have some photos of what it looks like now somewhere.
The lighting has been sorted but we thought the other ceilings were probably in a similar state so we had someone check them and they were, so they are all being sorted. we found some .75mm flex twisted onto the 1.5mm solid cables. it is amazing what a suspended ceiling can hide!
I took my time, I hurried up, The choice was mine, I didn't think enough