The old first gen LB-100s used (generally) a Gotoh pickup that was pretty non-descript and generic looking. So I wouldn't be surprised if you really did have the stock pickup in it. They were wound to spec for G&L, who requested an extra 500 turns (5% overwind) due to the location of the pickup. These were typically the ones in the white covers, and the Armstrong pups were in black covers, but the Gotoh coveres weren't affixed to the pickup at all, so it is easy to swap them out for a more traditional black.