I have got a whole car of spares there yours for 4.5k . I cant remember exactly what i have got spares wise, i know i have about 6 alternators and about 7 flywheels for some strange reason !

Ive got a nearly new radtec 500 cooler the 60mm thick one, front diff a couple of boxes of odds and sods and some random 3dr bits.

What needs doing to your header tank ? I might be able to take it to work and do it for you.