I have been under and had a look again. The sump seems very vulnerable, and also the clutch/gearbox.
I have to wonder that it needs something in steel.
There are 4 threaded holes in the chassis to bolt into, but they are not placed as far back as the sump, so it would have to be thick enough plate to span back, and do the job of protection.
I am going to make a mock up in cardboard and see just what the job is. I will have to do something. It is a big bill waiting to happen.