A few days after photographing the invasion, he was thrown out of a screening room by an Army lieutenant who declared the film top secret and threatened to court-martial him if he viewed it
That sounds exactly like the military. Catch-22 is closer to fact than most people realise

Can't help you with the Glenn Ford thing, other than Redlegs suggestion to get his serial number and pull out his service record.

I can add a couple of fought in WW2 + Hollywood names though. Richard Todd played Major John Howard of the Ox + Bucks Light Infantry attacking Pegasus Bridge in The Longest Day - he actually was one of the soldiers in the attack IRL. Stephen Ambrose mentions it in his book, so I'm pretty certain thats true.

Christopher Lee worked in cryptography for the RAF in WW2 and is supposed to have served in the SOE as well - don't know how true the latter is though. Peter Jackson said he got told off by Lee when directing the stabbing of Saruman in ROTK, "thats not the noise a man makes when he's stabbed".