I want one of these!!!This guy did a terrific job custom building his tricycle. Has a very good likeness to the child sized ones I remember from years past:
Adult size Replica Radio Flyer tricycle for burning man 2011 - YouTube
The kids' trikes from the '60s on back were made much more solid like this custom adult one and could easily handle teen and adult weight. I've got several of them from the 1930s to 1950s and occasionally ride one around the basement. They pedal real easy on their ball bearing wheels.