http://cgi.ebay.com/CAMERA-PARTS-BAR...ht_5010wt_1112

I have no relationship with the seller but just saw this and it makes you wonder just how light you could get it... ? It actually looks practical, just add a common Sinar back to the frame.

The only real work is the aluminum block they must have screwed everything into.

I wonder if they can get the front track to fold and close?

Seems like a butt-simple wide-angle handheld field camera to me.... maybe not with a 90/4.5 but a 90/6.8 to 135 press-type lens would work well.