Awesome idea.
I'm the guy who did that thread in the-coli . Pre-2000 is very difficult to know what numbers are 100% credible. Hell, most of the ones I've got from the Observer change from time to time too (I've seen Dave report Wrestlemania V doing 780,000 - 767,000 and like 725,000 buys for example).
Nowadays you get like 2 or 3 reports for the same PPV and it's never is the same number . I tried to always put the latest information on every show, but I'm sure there's a couple of PPVs were there is more updated info.
When it comes to ECW, I remember listening to Dave Lagana's podcast were he told that they were doing between 90,000 and 60,000 buys at their peak.