As you know, the amps cannot be "switched" to triode; there is no switch. However, they can be converted to triode. But I would not do it. A friend bought a pair that have been converted to triode, and has not been able to sell them. They are currently listed here on Agon. Modifications are bad for resale, especially to classic pieces like these.
Why are you concerend about having too much power? Most problems arise out of not having enough power. You have a great sounding pair of classic amps. Tube life is very long on these amps. I would just use them as is, and enjoy them. Leave them alone! There is a reason these amps sound the way they do. Do experiment with input tubes. Tele's (real ones), Miniwatt gold pin, are my faves.
Good luck.
Why are you concerend about having too much power? Most problems arise out of not having enough power. You have a great sounding pair of classic amps. Tube life is very long on these amps. I would just use them as is, and enjoy them. Leave them alone! There is a reason these amps sound the way they do. Do experiment with input tubes. Tele's (real ones), Miniwatt gold pin, are my faves.
Good luck.