I recently acquired a nice Rotax-powered two-seater, but am hard pressed
for storage. So I might well want to store it on a trailer, that I could
well build myself. Friends I consulted seemed to take it for granted I
begin by welding together a frame of steel profiles, paint it with
primer and gloss, then attach an axle and a few other paraphernalia.

But why not bolt together a few lengths of aluminium? No need to paint
or weld - or is this over simple?