Wow. Only four views and zero replies in over two hours on the board — in the middle of the day. This thread’s drowning, pal!
Let me see if I can help. I once tried to get Neilsen ratings too. Unfortunatately the Neilsen Co. was very strict about denying me such info, even though the ratings I wanted were absurdly old (well over a year), just for one day’s worth of broadcasts, and for purely personal reasons. They insisted I buy them (or – and this was probably a frowned-upon sympathy suggestion – ask one of their subscribers to give them to me, which I never did.).
I did try the public libray (the NYPL, no slouchy little one-room outfit in the boonies), but no luck – they do not subscribe.
I guess you might try a big university with a media/communications dept. They probably don’t subscribe either, but if they do, they probably won’t mind telling you what you want to know.
The main Neilsen subscribers are ad agencies and TV stations. Maybe you could coax one of them to help you.