did you explore the possibility of a tandem sprocket instead of side by side?
It seems like there is some room behind the frame loop to put a dual sprocket coupled with a chain guide with rollers to keep the chain taut and drive the two sets of sprocket, and then it seems like it would be possible to install the clutch and gearbox where the toolbox is on a 950.
This would have the whole drive to the transfer inside the frame perimeter.
But you are the one doing the cutting/welding/sweating and experimenting though.
Maybe you have even explored that road?
Keep on the good work.