The internet says the plastic porta johnny was patented in 1960 and fiberglass shiters were soon on the market....So they are traditional. That tracked skid loader? Small crawlers had been around since the 1920's..Guys push the rules saying since PS AC etc was available on 50's cars , that makes it ok for a chopped model A... So we are all good here... Oh, and theres the cobra head area lights, mini van, boom of all terrain fork lift and a side by side wheeler.....lol