Like Andy said, there is nothing you can't learn or figure out.

You've ridden it at an airfield, one sniff in the tank (or the exhaust when it was running) will tell you if it was pump or race fuel.

A few weekends disassembling and measuring everything will yield enough information to know all you need to know. You also mention who built the engine, so a call to them will answer a lot too.

Jets are cheap. Lots of new spare still available from Honda, Sprockets are easy, you can buy alloy blanks and drop them with your existing sprocket at any half decent engineer and they can machine a match.

Won't be hard to find a front guard that can be made to fit. It's only fibreglass.

In all seriousness, If I wasn't on the cusp of buying a house, I'd buy it and get my mate in Amsterdam to collect it. Arrange shipping and get it another aussie scrutineering sticker or two.

GP machines in worse condition trade for more.

So....what are you waiting for?