Window advice

Morning all, hope you're all keeping well. I'm in need of a bit of advice. I've taken the rear passenger side outer plastic panel off to expose the whacking great big L shaped hole AS originally cut out for the fridge vent. I'm thinking about just cutting the entire window panel out and fitting a privacy window as I'm going to have the sleeping area at the rear. Where can I get the window from??? Everywhere I've searched for windows they don't go that far back for Mk3 ford transits! 

Also the old air vents in the sides of the fibreglass roof are just open to the elements,  what's the best way of making them more closed in and better against rain etc? Any help would be greatly appreciated. Many thanks :)

Might be worth trying: [You must be registered and logged in to see this link.] based near Beverley East Yorks. They have helped me out with older items in the past.

I ended up getting a chap over to have a look that converts vans and he said to just patch the how up with a plate and keep it looking original so that's what I've done. Rivets,sealant, tape and threatening words seems to have kept a new panel in place ready for another 30 years haha