Defroster Vent Help

I am restoring a 1959 Ford F100 w/ a 292 V8, 4 spd. trans, step side.
I am at a point where I am stuck and can't get past w/o some input and thought someone that has gone through this and might be able to assist.

I am talking about the defroster vents. Underneath the dashboard and the defroster slot is Ford's better idea of defroster vents. Stock, they are paperboard vents. And mine are torn. What would you suggest to replace them with?

I would like to find something a bit more durable in the form of some plastic vents off of a vehicle with comparable sized defroster vents. The Ford's vents are approximately 19" at their widest section just under the dashboard. And, they are approximately 1" wide at the top also. The inlet hose is approximately a 3" diameter.

Any suggestions would be appreciated.  

I had restored a '59 and you know I did not take have mine out. Cardboard, that is a surprise. What I would do is adapt some from another truck that are steel. I know that the '48 through '56 Ford trucks are steel and one could fit these to the '59 as you can not see them . Now these are the actual piece that goes directly to the bottom of dash?.
Measure the slot on your truck and find the steel one that will fit and form an adapter plat. Dude  

Sacramento Vintage Ford has fiberglass replacements in their catalog that fit right in.  

Thanks. I appreciate the response!
I have e-mailed Sacto Vintage Ford and will wait to see what they have for my Ford. I would definitely take fiberglass over steel.