Nice 'soapbox' cart. A thing rarely seen for many a year but as kids we were always scouting round for replacement parts, better technology and ideas. Like Meccano etc its where engineers came from with dad's round here only really offering safety monitoring and support in out of bounds tooling. Fun to learn the basics and all practical skills. Engineers out of books, I think not. You have to have the practical ability to start with. I never produced such a civilised one as your though. We were firmly into speed and strength for collisions having a good hill nearby and the occasion when dirty tactics would be employed.
'Dresses'. Of course. Simple to make and keep clean, less wear than trousers if you have the sort of child that is clearly perfectly happy having pranged the trike and probably into everything. I had the family baby wear including the famed 'Scotch Panties' for best. All our child's stuff is passed on for re use. Buy new, got to be loaded! Its what made Britain great and got you ready for public schooling. (I refused to go to Bristol's QEH as they had a uniform including a skirt thing and cape. Wonder if the still have?). However it will be interesting to see how much of this old stuff my Niece will use shortly. Going to be a great uncle, all the more reason to be more eccentric.
I guess the Thunderbolt is long gone?