Hello dear mylespaul community, since I had some trouble with the volume potis and was looking for some thicker sounding PUs I completely replaced the electric parts of my ES-335. The guitars head plate reads the following number: 8141002. If I'm not mistaken this number indicates 1980 as the year of construction and Kalamazoo as the birth place. Feel free to do your own research. It has come to my attention that the original PUs built for this guitar have been designed by Bill Lawrence, who worked for/with Gibson in Kalamazoo as pickup designer after 1976. The PUs are low impedance pickups specialized for studio recording purposes. Again, feel free to check this yourself. To come to the point: I sell both pickups to somebody who is interested. They come with a split switch and the two corresponding tone potis; not the volume potis, though, since they are unusuable. Best regards!