The new reissue Mullard 6V6-GT vacuum tube is a great choice for your small Fender amp or any 6V6 tube amplifier. It has gray plates and a top "halo" getter.
From our review: "The sound is exactly what you expect with any good 6V6. They have sparkle and chime at lower volumes, and the notes thicken and bloom as you increase the volume. When wound up these little tubes can yield a wild amount of crunch to a fluid overdrive. These would be great in single end amps and will make your Deluxe Reverb bark."
From the manufacturer: "This valve is built to stand the high voltages encountered in the Fender Deluxe Reverb and other guitar amplifiers that ran the valves above the published specification. The smooth and balanced frequency response also makes it suitable for hi-fi use."