I also noticed that the 1950's bridge has a much more pronounced radius than the later one which is nearly flat. This means unless the setup included adjusting the string and pickup height, as well as the pole piece screws, the distance between the individual strings and the pickups could easily (and more likely) account for that difference in output and balance. The high and low E strings are going to be much closer than the middle strings than with the later bridge if no adjustment was made. I said I would be very surprised not that it was impossible, and I remain open to convincing but still unconvinced. If he had played both bridges, and then also played the later bridge with the wire removed and demonstrated the same difference it would be a bit more convincing. I would still need to be in the room and actually observe the set up to be 100% convinced. I like vintage gear as much as the next guy, but a lot of these claims need to be taken with a whole shaker of salt.