For those who believe all the Marx prototypes are in significant collections this is proof that they're not. This turned up in 2009!
SCL gondolas are lettered in black. I found this one along with several solid color gondolas but did not realize the lettering was
red until after the auction ended. I was bidding on the brown unlettered gondola shown elswhere on this site!
Just about the time I found the red lettered SCL gondola a collector from the west coast turned up this yellow Pennsylvania gondola. He was kind enough to turn one of the two over to me.
(Courtesy of Steve Eastman)