Thanks mihcmac for the thorough answer. My son says he "doesn't mind the hum" but it is frankly annoying to listen to for the "audience" (The wife and I). I've explained some of the options such as shielding the cavities (if that's even available for a full hollow-body), gates, and reversing the magnets in one of the pickups as you've outlined above. As I understand it, that's basically what a humbucker is, two single coils adjacent to each other but with the magnet poles reversed on one of them. Being pretty technical and handy, it seems like a project I can handle with success but his main concern is that reversing the polarity of the neck pickup magnet would affect the native P90 tone/sound that the Casino is known for. (and thus sounding less like John Lennon and the Beatles of course 🙂 ) BTW - NIce 339 in all its Natural Beauty!!!