The method you described will NOT allow for complete shut off of fuel supply, a particularly dangerous situation for fuel thinned oil (and lack of proper lubrication) to occur....
You are FAR better off leaving it as it is......
As to Ohio Cycle, I wonder how they explain a five speed part number (-292-) on an earlier four speed bike (-283-) if it wasn't a replacement...A -283- part I could understand, but then WHY change it to a -292- number (different part/same usage) when the 5-speed engine/bike already utilizes MANY -283- parts ...The -292- part numbers didn't exist until the 1968 K1 models........
Perhaps Bill, Nigel, or Ronny will correct my (obviously failing) memory.......