Good and bad.

 

http://www.youtube.com/watch?v=TtaDH4LPxf0

This is the most complete he's ever been.

Unfortunately, you can see around 35-42 seconds in, the third wheel is wobbling. A lot. It's a problem I'm not sure how to solve with the A&A foot... It MAY be related to the way it is mounted, but that part doesn't seem to move.
The ankle area where it  joins together seems to be the  problem, but a nut will not fit in the side "channel" that gets covered, so there isn't one in there. Just the bolt. It's surrounded on one side, and then stopped at the other, so it's not going to come out...
It seems the problem is just related to having so much weight on such a narrow area with the two wheels lined up like that.
The problem is, the casters I've been able to find so far are all too small or won't fit under the plate without knocking into each other. I had two small 1.5" wheels under there yesterday, but they would not swivel. It seemed to be related to the weight, but I'm not sure.