Very cool - there doesn't look like much distortion in the floor panels from the photos.
I'd wondered whether to try to get a chassis galvanised. Normally any thin flat panels will buckle with the heat. That one doesn't look bad, but there's an Aston Martin chassis in the garage with maybe 10mm of buckling in the floor panels. Could depend on the galvanising company.
Chassis looks standard GTL to me with lots of other parts welded to the frame they are selling. Can't believe that frame is stiff enough to be of any use.