I have totally disassembled the amplifier, and removed the power transformers.  I then rewound my own, for higher voltage.  The amplifiers rail voltages have gone from 50V stock to 61V now.  Output voltage has gone from 31V (about 240W@4ohm) to 39V (about 380W@4ohm).  Several other components were replaced to make this improvement possible.  The amplifiers preamp, or "front end", has been totally reworked to perform the same as the original MS2250 from the early 90's.