I worked for a guy called William H Bird and he and Willis were often confused. They were buddies as they had some mutual business interests, particularly in Lao. At the time Willis was supposed to be the Thai representative of Safety Insurance but I don't know if that was true. My understanding was that Willis could not return to the States due to some legal difficulties but, once again, I cannot confirm this as I was a very junior and uninformed member of that clique. William (Bill) Bird had a large construction company in Thailand called Thai Rock Products (where I worked) and also another company called Bird and Sons, in addition to his aviation interests. Very colorful characters.
Bill Bird