I have never seen a speaker with the model of the amp it went into printed on the back. As well, the 12L6 number is what one would expect to see on an Oxford yet this speaker has a 328 code which is Utah. This reconed Utah sounds perfect. Vintage type cone, aluminum former voice coil. I treated the surround, like it originally had, and as the last picture shows, some minor dimples appeared. Has no effect on the sound. This 8 ohm speaker has been tested and played through. It was run for over 2 hours at 40Hz to break it in. 45 watts.