Since the Forest Service had moved the batteries to a location under the hood, I don't have the battery box in my cab. With two boys, it was a bit tough for all "the Taylor boys" to have fun driving around in the M715, since there's only one passenger seat. So I got a Deuce passenger seat from Mike that I adapted to fit.
Here's what I started with:
I wire-wheeled the rust and flaky paint off the frame, primed it and sprayed it USMC green. I threw out the old covers along with the nasty horsehair and rusty springs, cut out a new base out of 3/4" plywood. I got 4" closed-cell foam for the seat base and 2" for the padding on the back and got a new set of canvas covers from Mona at New Life Canvas.
I cut off the front left leg and shortened the others to fit reasonably close to the stock height of the driver's seat. Installed a third seatbelt and now I'm good to go!
The seat back still folds down for a nice diamond-plate base and the seat bottom flips up for access to underneath. Perhaps I'll put a box down there for loose stuff.
It was remarkably easy to make this modification. If anyone would like detail pics of my hack-job on the legs, just say the word.