Well we done the doors and bolted them on.Then found out the frount guards were differint, right side is shorter by 10mm at the door and did not line up at the bottom.It looks like one of them re/makes, has a number half way down the iner guard.The other side has name stamped at the first bolt from the frount, it fits ok but can not make out the name.Have any of you blokes had the same drama.Is for a B210.

From my understanding of your description my mates guards are the same on his 120Y wagon. Its like the guards are too short in height. We just bolted them on and so the bottom can be bolted up we had to leave a big gap between the bonnet and guard, it would be around 10mm to short like yours.
Oneday and I mean oneday we will split them down the bottom and extend them to fit properly but for now the bonnet to guard gap is negligable to us as it brings with it the extra bonus of that mad wind whistle while driving ( onday it will get fixed )

Its my understanding that cars around the age of some of our beloved dattos weren't built the same way as cars are today, and so panels had anywhere up to 10 mm difference in them car to car, possibly more. this is especially true for panels such as fenders. so that perfect fender you found somewhere isn't always going to fit, even though it could have been on the next car off the production line.

There may possibly be a diferent level of quality control these days, but even in the 60's they weren't that bad as far as panel fit is concerned.
I suspect that Holeshot may be on the right track. It would seem that many of these "replacement" panels are made with worn dies that the parent manufacturer has sold off. At least, thats what the car makers would have us believe.

Hight is not the problem,length from door to headlight is.We just ordered new L/R frount guards $176.00 AU for 2.

Spare parts place rang the the supplyer and said yes we got them so money is paid.Two days later went to pick up guards and parts man said there is none in AU.I smell a rat here,so I said keep looking some one is going to get me some guards I PAID FOR THEM.There is a law isnt there about taking money from you when thay say thay have it but dont.

Had some spare time this arvo, so went down to NISSAN to see if guards are still in stock.YES said man from NISSAN,$235.00 AU a guard.Looks like I will have to make a floppy mold to make fiberglass ones.Think I remember how to do it and what to get.

HOLLY BATSHIIT!!!!!! that has goto hurt the wallet

You think that this is expensive, then get some prices for the same part for most any late model car that you can name.
They don't give anything away.