Spark plug heat shield question on 67 GTS

I was working on changing the plugs and wires and noticed a spark plug heat shield on the drivers side for the two center plugs looked wrong. Like they put it on the wrong side after the engine rebuild. Anyone know where the heat shields should be located on a 1967 GTS 383 Dart? I don't really remember exactly and I'm not sure they all had one. The rear plug on the driver's side has one and there's none on the passenger side now after the rebuild. :|

Also what holds them on? Head bolt? Exhaust manifold bolt?