I made my own plate which was a piece of 3mm ali and letter punched "haynes roadster" built by M.Gates thats me by the way
and also the date of manufacture, i used the completion date of my build: April 2010
You can buy a proper plate for the job which i think ash did (think i saw it on one of his photos) probably get one off ebay
Obviously had the chassis no. punched on a plate attached to the bulkhead and also stamped into a piece of 5mm plate and welded to the chassis bracing in the engine bay
Im guessing by these questions that you arent far away now?
