Yep pretty much as the title goes, I need the lhs air tube from the nose come to the frame spare.

I've found one for around a tenner but is that a reasonible price?

Also, what's the point of these, are they like the nc35 tubes and are just for show or do they provide a purpose ?

I guess like the 29s they are for show or some vague 90's reasoning. I read somewhere that the 29s was to alter preassure just behind the rear of the carbs to better the air flow. I suppose that was the theory but whether it actually works, no idea.

the tubes on the 88 & 89 models J & K are different. make sure you get the right one. tube feeds into the airbox but how much ram air you really get I do not know.

They are for anti peculation! To stop the fuel from boiling in the carb, R5 turbos and X1/9's used to have air ducts with fans for this reason.