OK taken the input shaft out of the gearbox and the needle bearings have disintegrated to such and extent that there are no longer any needles just the housing which is bent and twisted causing ware to the shaft and aluminium casting.
Still trying to get one of the needle housings out of the casting, not sure I can salvage the casting, there seems to be room for 3 needle bearings not just the 2 shown on the parts list, so it might be the case that these are not the original needle bearing and at some point someone replaced them with two that were not as long.
Nath you are right they still do parts for the 700 series and there is a company that makes an aftermarket replacement, it seems the 700 series is the gearbox of choice for people building go karts in the USA. Here is a link to video about the 700 series
So will see if I can repair mine, is there anywhere in Australia that sells imperial size needle bearings or will I have to get them from the USA?
