Definately not Mad
Stark raving bonkers maybe
Read the book a couple of times ..... Decide if you wish to source the steel for your chassis, then cut it yourself .... Or .... Buy one of HandyAndys excellent flat pack chassis kits ... Bargain if your build time is limited or steel is expensive locally
When you start building the chassis, this is the time to start looking for a donor .... Have patience, one will come along when you least expect it
Lastly .... A very warm welcome to the forum, enjoy your build