We have different types of ellipsoidal fixtures in our rental stock. Source Four HPL’s, Source Four LED Series 2 profile spots and ColorSource Spots. On the Shutter Barrels is the tekst "Source Four 750", 'ColorSource SPOT" and "Source Four LED'. But all the Shutter Barrels look the same. Can we also use the “LED” Shutter Barrels with the HPL lamps? Can we use the Shutter Barrels interchangeably?