Windows were factory optional but a lot were put in aftermarket also. Are you after a restored van or are you open to restoring one.

If you are not much of a panel beater than an unrestored one is probably not a good idea unless you want to learn. I have seen quite a few good complete original vans come up but all needed some panel work, three have been totally original rust free cars but were farm vehicles and had a lot of panel damage.

I bid on this Aquarius 308 4sp original Sandman ex farm van on Ebay last year, the $8000+ winning bid was a bit more than I was prepared to pay at the time for a pretty knocked around car, just about every panel was damaged. Would have been an excellent restorer though.