Funnily enough I encountered a very lovely Vitesse 1600 at the weekend when I was out and about in the Somerset countryside with my dog in our 13/60 CV. I chatted about cars to the owner for a bit as you do and I remember noticing that his hood was a mohair replacement and that he'd folded it with the largest flap (the rear top roof section) pulled back and resting neatly on the rear panel rather than pushed down into the well as original spec. vinyl would be. After reading your post I now see why he folded it that way. There's not a lot of room for hood stowage, and I doubt you'd want to risk premature wear or damage to the rear quarter windows by forcing the heavy mohair out of sight, so perhaps his method is the way to go as it still allowed the front rail to lie almost flat and everything looking neat.
I fitted a new hood myself in the Summer but chose vinyl - mainly for ease of fitting but I also thought that perhaps the heavy-duty and non-elastic mohair might be a little much for the roof frame's longevity. I am probably wrong on that count, but as with all non-standard mods there always seem to be issues to resolve or compromises whether it's hoods, wheels or engine swaps. As long as your hood fits nicely and looks good when up, which I'm sure it does, then I guess a slightly bulging fold is no big deal...