I do on my tractor. Little more modern material, but the same idea.
If this is what I am thinking it is, I would be curious on where to get one.
I hunted with a boss of mine that hunted on the Kennedy years ago when I was in HS. They had a International scout that they hunted out of. It had a "pillow" of sorts that was secured to the hood. It wasn't inflated that I remember, but it reminded me of a blow up air mattress. It was made to where you could put your rifles inside or simply lay them on top. I have been looking for them for a while and haven't been able to come up with anything.