No answers, but some thoughts.
I could see where the El Camino and Ranchero would be disallowed, and not because of the fact that the bed is part of the body - it was based upon a car would be the reason. I believe the 1959 Ford F-100 also incorporated the bed into the cab, yet it's clearly a pickup, to my mind.
But the SSR was, from design through production, intended to be a pickup truck.
I can't speak to the valance, but it sounds to me that they may have got this wrong for 'em.
I've got a bit of an interest in this small pickup question - I'm sitting with a 1 liter AH engine in the Midget, and thinking down the road a ways, a Morris Minor Pickup might make a good home for it.