Pedro, I lucked out on mine when i bought out Fred Fourg in Wichita an old original AR dealer .. Fred was a real gem from Germany and sold all of his inventory to me while I was in KC. Need a Column shift doo-dad for a AR Giulietta Ambulance .. I probably have it? Anyway I drove down in an SUV and picked up everything and his inventory list... Nothing laborious like engines or even bell housings or shafts was included and everything was on printouts. Mostly stuff in bins he had to keep on hand as a AR dealer. Asked him if he would sell the sign.. he said no he would give it to me and deliver it because his son in law was going to KC the following week. It's one side of the two sided lit sign they are asking nutty money for in the Canada ad. Just one "lens" ..It's hung on my barn door that separates my office from my garage. They were going for like $800 years ago ...A little trouble shipping but they do ship pianos... NOT for sale but it is about 57"O.D I think you can find them but you might have to do some ambulance chasing... Fred and I only met that day and by lunch he was like an uncle to me.. get it?
Maybe Difatta has one they'd be willing to sell since they're closing out. I know they had a rectangular one from the early 60's pictured on their ebay auctions, perhaps the have a round one in the back? Might be worth a call.