Technical 1951 Cadillac ambulance windshield options

A friend of mine has a 1951 Cadillac ambulance and is having trouble finding a windshield. The one he did find is for a car and it didn't fit. He sent me these pictures.
He asked me if it would be an option to weld a car windshield opening in the ambulance but that looks like a can of worms to me. I haven't seen it in person but he said it has a fiberglass top. I thought someone here might have an idea.

 

Might try asking "the professional car society" folks.

 

I just looked at that forum. Thanks for the advice but it looks like a pita to join. It looks like a good group for the guy that owns the ambulance, I'll send him a link.
Edit I found the forum page. Thanks!