This is actually dolly version 1. I have a version 2 in mind, but it's one of those when-I-have-time projects, and is far more versatile (and complex). It will require me learning to weld aluminum with the MIG welder, and to be far more precise with machining parts.
I may split it into two parts: there is a logical division between the camera elevator and the new dolly platform, and I can build the camera elevator first to retrofit on the existing dolly platform. Modular design is a good idea.
I'll add it to the project list.