Somebody, anybody, please do something positive or move on and enjoy what you've already got. This pre 90 saga has been going on for at least two years with bugger all happening because nobody has the goolies (
sorry Adrian, I don't mean you) 
to do anything but post their theories on a forum. If HEAVEN have shown reluctance to change their charter, go to another club and float your proposal. There are a number of clubs that are going through flat periods that'd love an opportunity to increase club membership and renew activity. We did it with Penrith years ago and Shoey, Ribbo and Husky Pete did it by going ito cahoots with Manly club to get Vinduros up and running in NSW.
This forum talkfest is becoming tedious and does nothing but create angst within the vintage community. Nobody's disputing that pre 90/95 won't be a part of the future but the big question is whether it's right to lump these late model bikes in with bikes from earlier eras. If Nathan, Sugar and the other Pre 90 advocates have steadfast belief in the future of post 85 motocross being a good thing it's time they as a group stopped talking and started doing.
If I was heading the pre 90/95 proposal I'd start the ball rolling by first up calling a meeting for all interested punters via posts on forums and press releases to all of the magazines to be held at central venue to test the water and create some sort of brains trust to help rough out a sensible proposal to take to a club. Because Penrith and HEAVEN are offering their own brand of vintage racing, I'd be looking at presenting a package to a club that offers a slightly different product than what the other clubs offer. Offering them a package of say....Pre 90 and pre 95 plus and perhaps a two stroke only modern class.(
this is merely an example of a proposal that wouldn't significantly cut into HEAVENS base structure). To push this new concept it's imperative to approach the media including magazines such as ADB and DA with a well thought out article describing what you're proposing, emphasising what makes it different from traditional vintage racing. Having a media heavyweight backing your new concept is an important key to selling the class to new market. Offering a bike for said media mogul to race at an event is one way of getting the desired magazine pages. I'm positive that most new racers for the class would be drawn from the modern ranks so that's where most of the promotion should be aimed. From my experience with the modern motorcycle media, they have little interest in pre 78/Evo style racing but I'm fairly confidant they could relate to the pre 95/two stroke motocross as the bikes fit into their demographic far easier than twin shock bikes. I'd also be hammering all of the Aussie motocross forums with the idea, once again emphasising the difference from traditional vintage racing which most young 'dudes' have no interest in.
Of course, all of this takes time, commitment and great personal sacrifice. It's not something that will happen overnight and will require patience and the ability to handle rejection and scorn without publicly spitting the dummy. It took me two years of lobbying and letter writing to get a foot in the door but I was convinced I was right. With 21st century internet communication including forums, websites, facebook and other social media outlets, the message is much easier to distribute so I reckon you could cut my two years of work down to six months.
I'm basing all of the above on my personal belief that these proposed later divisions don't belong under the VMX banner and that their spititual home is tied in within the modern movement*. The ever growing VMX class structure must eventually become too crowded so the pre 90 or pre 95 cutoff is probably the right place to start the separation process. Both different divisions can coexist with cross promotions possible and, in the beginning encouraged to make up the numbers.
There's a few hurdles to jump but it's all possible if you want it bad enough. All that's needed is a driven individual to oversee the whole process.
*
(Purely a personal opinion, I'm prepared to be proven wrong.)