Ray, I sort of think you are right. I was told a while back that it was from a propane conversion of some sort. Whether it came off of a conversion or what I don't know. I'm nervous about showing it with the casting but it sure looks good.
Mark, I think K&N sells an air cleaner that doesn't have a logo on it. It is perhaps shorter than yours. A good scuff job to scratch the paint and a shot of black should solve the problem. I'm thinking that is perhaps the best way to go. One less thing that would stand out and draw attention.