I have an old Alamo Montclair 2565 amp that has a solid state preamp and 2 6V6 and a single 12AX7.
I want to know can anything be done about getting the amp to break up more?
I have replaced the tube with a 12 AU7 and it helps but not quite enough.
Are you asking about doing mods to the amp itself? It should have the same circuits as the old fender amps. You could try a equalizer pedal an a overdrive pedal to overdrive the input. A thought would be use a tube pre-amp pedal or rack mount and racked equalizers. if you have a speaker out you could also put an attenuator on it and cut about 4db and run the amp harder. You'll lose some volume wise, it should breakup nicely thought. I use a tube pre-amp, equalizer, attenuator on my old 12 watt Gibson amps and they break up real nice.
Another thing would be the speaker. The difference in speakers can mean the difference between and day. maybe add another single speaker cabinet with a different speaker. Just a couple thoughts.
Joe