Here is the 'finished' version
http://i.imgur.com/fBHiik0.jpg
Here is how the output shaft is actually held in. (spacer, bearing, and plate hidden)
https://gyazo.com/7331d2fcb0f597dad4bb6db74bdbd5d2
and here is it on the WCD itself which should answer the question about what its mounting to
https://gyazo.com/cc8580fe4a5277e981f19836fc12c0c6
The WCD is a WIP. I still have to model the belts and shafts on the outer wheels and figure out how I want to layout the frame with the shooter. Before anyone says there is not enough support with the corner gussets I should mention there will be a belly pan.
Even building the rest of that WCD will be really cheap. All we have to buy is the Versablocks and CAMs.
So.. yes we are building an entire drive train for $166. The only parts I am not 100% sure on is hardware but in the end that's pretty negligible and I am pretty happy what I was able to make with our stockpile of parts.
Also, I may be attempting a flipped CIM gearbox soon with the same goals. Due to the crazy thickness of the pulley there is room. If that works out we will probably build that.