As your father is breathless after a few yards walking, why not get him an electric cart
. If you look around I'm sure you'd find something suitable with enough range to view even the gigantic RIAT static park (and back!).....just a thought...best of luck anyway...
Is there a 'spotters car park' at Marham? If so get the electric cart [plus umbrella, bottle of whisky and a few turkey sarnies) and give him a couple of hours close to the runway). He'd love that! He would come back smiling but deaf!!