Looking good.
Something to watch out for, that front end is going to have way too much rake. It will be very uncomfortable to ride. There are ways to cheat the forks to compensate for that, so ask your helper friend about that.
I preach to people about rake all the time, they don't listen, and they later admit that they should've listened.
We looked at that and I don't plan on keeping it at 4 feet... we are going to shorten it a lot so that it isn't so uncomfortable to ride. We are going to mock it up and cut it down so that the bottom of the frame stays parallel to the ground... I don't know exactly what the length will be at the end yet... but definitely not the full 4 feet like they have it! Good call though, I definitely want to be able to ride this!