I went and picked up the engine today for $750.
The engine has had a rebuild before it was sold to the previous owner 2 years ago, since then it has been sitting in his shed under a plastic tarp and has been manualy turned over every month in an attempt to keep the internals coated with a film of oil.
The engine and head are fitted with new welch and coolant plugs, new gaskets for the intake and GX twin exit exhaust manifold. The intake manifold, air filter housing and twin hitachi SU type carbs are very clean and in original condition. I didn't buy the mikuni carbs because I was having huge dramas finding a spare parts shop for them, instead I am buying a pair of Dellorto DLHA 40 carbs for $270 and I will need to buy a manifold to suit them and the GX oval port A series head, so if anybody has one for sale, I'm your bloke! also if any body would like to buy the twin hitachi SU carbs, manifold and air filter housing, you know where to find them!