FOUND..... Late 70s Plexiglass Rad Ramp Halfpipe

Found this Original 70s Plexiglass Rad Ramp Halfpipe. Hidden at a farm since the 80s... We believe it was the one outside the Surfin Turf skatepark in Milwaukee in the late 1970s. I was told by one of the original Rad ramp guys, that less than 20 of these half pipes were built.