Thanks Rusty, but all is ok now, so dont trouble yourself. I just went and bought sets of three ranging from 8mm to 13mm. The 10mm balls were the best,fit for future reference.
It was just a matter of finding them, believe it or not. No-one i spoke to could supply just balls, they were all encased. Almost got to the point where i was about to spend $100plus on bearings just to crack them open. Anyway, a weeks searching and i found them.
Pete, my garage has a bench, and thats where i was working, i just didnt expect my "balls to drop" onto the floor right into the funnel shaped bit of concrete surrounding the drain

So all is good now, and what a pleasure it was to to do a complete reco on the gearbox. I have always strayed away from rebuilds on any mechanicals on the little nikis mainly because replacement parts have never been a problem for me, its always been remove and replace and away i went. The times are changing though, and being as rare as they are already (in Oz) the replacement parts are getting to the stage where they're not better than the old. I guess I'll need to make offers on the ones i know are still out there. I know of a couple sitting in line, about two meters from the side of the road, but you cant even tell they're there as they're covered in bush, weeds, and who knows what else

I must go see if they're still there. Sorry starting to ramble........
Thanks for your help