No value? Stock engine on Stearman's, various Waco's, PT 23, Cessna 190. Hardly no value.
I should have clarified my statement. The tank versions, which are were widely available as surplus, only had a single ignition system and, therefor unuseable in aircraft.
For those unfamiliar with piston engine aircraft, pretty much all of them have dual, independent ignition systems. 2 magnetos, 2 spark plugs per cylinder. This is redundant safety measure. The w670s for non-aircraft use had only a single magneto and the cylinders will only accept one spark plug.
While it's not possible to tell from that video if that engine is the aircraft or tank version, I'm making the assumption that it's the tank version given their relatively wide availability and limited use.