PHD2 Rebuild

[Formas]

Hi everyone/anyone i have a PHD2 Earthquake amplifer that was brought to me to be fixed, actually it was scrapped (missing fets both power and output banks) the board was clean tho, so i told him that i will try to repair it, the parts or most of them are obsolete, but luckily i get my hands on a old inverter with 24 good stp80ne06-10, and PWM and Mosfet driver tc4424cpa and hip4080aip from different old parts (including a dhc100 mmats)
i need all the professional advice as possible that i can get in completing the repair of the amp.
what ive done so far is test the gate resistors and the power diodes, the two rectifiers, i also disconnect the rectifers output pins cause i want to focus on the powersupply stage first.
i powered it up with six fets both on the lowerbank and i get it crank up with 112volts at the center pins of the rectifier. i havent add the other 6fets yet. i would like to know if the PWM chip ( i think it is SG3525 it was scraped tho) is good, hence the oscillation. or if there is any potential damage when i load the upper half of the supply bank with the remaing 6 fets?