So it's James and a 306 owner, by the sound of it! Welcome.
Fitting 15" tubs doesn't alter chassis- not sure that it is legal to do that anyway!
The following pics are of a later small arched car. They were taken in the last few years but the suspension is supposed to be period.
Front end uses clever tension struts which probably were accepted because they were 'part of' the roll bar or something! Interesting feature is the tube running from wheel arch forward along inner wing, maybe shell strengthening?
Rear end as Stephan's pic. Car has lost diff cooler, but cover still has unions. Remember the races were up to 6hrs- don't think cooler needed unless you find a race of that duration! Guess exhaust is later addition.
The rear spring has an interesting leaf arrangement. Have never worked out why.
And lastly they still used centrelock wheels. Unless you have a lot of money to spend maybe not!
