Hi Ian,
Given what you originally said about your car I suspect it is one of the Older Kyoshos like mine.
I was after the Celica shell originally too but ended with with a choice of the Honda NSX (which I now have) or the AMG Mercedes Shells. Both of these at 280mm wheelbase length. (The Wheels on My NSX are as wide as yours but fit inside the shell perfectly) (It is 200mm wide also)
I ordered my shell from
www.alansmodels.co.uk and they provided an excellent, friendly and very prompt service in finding the shell for me (by contacting Kyosho direct) and providing a very prompt delivery too....!!!
The sad part is that they were planning on selling up the business when I ordered my shell, so I am not sure if they are still going or not....I think the idea was to sell the business as an ongoing concern so it is probably just in the hands of new owners now.
The website is certainly still live.
Try the link and drop them an e-mail...The other alternative is too look at the HPI Supersize shells, there are a couple there that will fit your car, Yes they are 200mm but have the extra width on the wings (as per real cars) so those wheels should fit in.
www.hpieurope.com
And to Other Iain...That Thunder Tiger in My pics is Actually a MK1 DT10 (quite an old car now)
Hope this helps...!!
Regards.......Mark