One of the biggest things to remember with that engine is that it is to be run on no less than a 24:1 mixture. Anything less and it will drastically shorten the service life of that engine.
The website folks have been directing you to is www.aomci.org
Go to the webvertize section and put up an ad for the parts you need. Always add your physical location to the ad header.
Go to the ask a member section for questions and you may want to ask around there as well for parts.
There are quite a few of us in here that can help you as well.
Almost all service parts are still available for that engine. They are excellent runners and a lot of power.