I seem to remember that they have 2 6L6 power tubes (which would make sense, since the RMS power in a push-pull amp relates to output, and I have a couple of 6L6-equipped lamps with about the same power as the Super) and several 12AX7s -- probably five, since it uses one for the reverb and tremolo.
Check for those at the website provided by Gitfiddle.
A friend has a nice '67 Super and tubes seem to last for a long time with "normal" use. If they don't have a mechanical flaw and they are not overheated etc, they will last a while. I have a Sears Silvertone Twin Twelve that I retube every ten years or so (I bought it in 1974), and a Music Man HD130 Reverb that I've retubed once, probably in 1995 or so. Both get used: I ran the MM with a Hartke bass cab for my practice amp with a band, and we practiced 2-3 times a week for a couple of years, and it's still going strong.
I love the sound of Supers. Now if they could only trim 'em down to about 20 lbs for us old guys....