When you look at the MK Indy a lot of the panels are very similar TT but where extended / widened by Mark, Fabby, to fit the wider Haynes chassis. It looks like the HSR body was designed to fit straight over the Indy but maybe the extra width and length of the Haynes would make it a problem. Martin did design the Chassis with Chris with the suspension geometry designed on Lotus software.
Maybe an email to Martin would give you the answer, i'm sure if anyone would know then he would:
martin@keenan7060.freeserve.co.uk
I'm sure its still this e-mail.
We do have an enclosed body shell for the Roadster but it's going to take an extreme amount of work to get it to a condition where it can be used.
Good Luck TT....AndyH