On my '69 Ambo with the factory "polizia" fairing, there was just enough room for the stock turn signal brackets to clear the bottom of the fairing and for the reproduction Harley FLH spots to avoid the crashbars at full steering lock.
Disclaimer: I've not used a Wixom fairing on any Loop, so the following is at best a guess based on photos of bikes so equipped.
Judging from photos of a Wixom equipped Eldo, it looks like that fairing can be used with the stock signal brackets (I'm sure many were outfitted that way "back in the day"). The issue then is if the spots will clear the fairing too.
Reproduction Harley Davidson FLH spot lights mounted on civilian turn signal brackets.
Close-up view of the mounting for the reproduction Harley Davidson FLH spot lights.