Craig,
There is some multi racing in Victoria, but I think it is mostly petrol. Talk to Craig Knight about it, he races one. 21 multi's still race in Adelaide with reasonable numbers.
The problem with trying to get Multi going again at a national level is the oval guys wont want run it, especially if it is just going to be one class. Even in Adelaide we run it completely seperately from the oval racing on different days. Where we run it would probably almost be dangerous to run 45's or larger. I could ask about getting 21 Multi on the Nats entry form, but it is not really a nats with 10 SA blokes and one Vic!
Where we race the driver rescues his own boat by wading in the water. Running on the oval racing water for X Multi would require the rescue boat to be manned. Unfortunately Multi is great to do, but dull to watch so getting people to run it can be hard!
Nitrocrazed racing: Will race for food....