[chrisguyw]

Chris, the fact he said 'a plastic shaft (just 5mm long), and a plastic wheel just go onto it'  leads me to believe independent floppy front axles but as you say the Chevron is SW and has twin front axles so could be swapped for one single axle right across.

...in which case 3/32" piano wire will do the job just fine

If in fact his car is a Chevron, (a sidewinder like all GB's, and all with sub axles )  the front body post will have to be repositioned in order to use a solid front axle, as the body post, in stock form, is in line with the stub axles, as outlined in my previous post  

Cheers
Chris Walker