Just read this through from start to finish - really good to see the progress that has been made from the beginning. Makes me want to buy so much!!! Anyway, first thing is to try and make another Jamspeed (TM) variant so I was looking at your pic above. Noticed on your cardboard one there are some extra bits, so I've added some bits to the picture to see if I understand it right.
There are 2 extra flaps not on the last post - which are to make mounting brackets I guess, to secure the heatshield from moving. There is only one fold, which I have added, what did you do to join sides A and B together? I was thinking I could add an extra flap then rivet it together maybe...
Have I understood it right - need to find some cardboard
Oh one last thing - what on earth is the edging called? Or where do you go to find it - I've been chucking loads of terms into ebay and google and cant find what I want really...
Keep up the good work!