I had a set with the NMW bar that I bought from Skip Nordenberg @ Suffolk Speed on Long Island back in the late 1960's. Used them to tow my Nova to E'town and New York National behind a 1956 Ford Country Squire Station Wagon. I lost a front wheel-bearing on the Nova one Sunday in Shirley, NY on the way home from NYNS and destroyed a brand new Stahl front-runner tire. I built my ramp truck after that!
Lew