Okay, here's the deal. I just picked up a vintage Kay, it looks like a Vanguard with the pickup set in the pickgaurd (third from the left in this picture http://kingofkays.com/images/kay%20misc.jpg). And from what I've gathered, it's from late '65 to early '66, I ended up dating the pots because Kay didn't put serial numbers on their low end models. What I'm wondering is there's some tape on the back of the pickup with a number. Does anyone have any idea if there's a significance to this number?