Excerpt:
Both the neck and bridge pickups were purchased from EBay through a trusted seller, so it’s not his fault. But basically, using my trusty Kobalt Brand digital caliper, it was discovered that the outside pole to pole distance on both of these vintage pickups are the same…precise to the nearest hundredth of a millimeter. The caliper tool shows this to be 55.50mm for both bridge and neck pickups…

http://alvarolupinacci.com/projects/