Alcoa Bus

I was given this bus when I was young. I have been moving it for over 30 years. It never had and wheels and always hoped I could find some for it. I have searched for many years for information on this bus, and have not found any. The only trademarks, on the bus, are on the bottom, from Alcoa Aluminum. I have never known them to make any toys, so I am thinking that it is either a promotional or display piece. I think the logo on the front of the bus, refers to Yellow Coach, but I am guessing. The double row of seats comes out (they are bolted in), the bus is 22 1/2 inches long and the outer shell and seats are made from cast aluminum. Any information would greatly be appreciated. Any guess on it's value?