Assistance with CFT-1800

[wild-gazer]

Hi all, a few months ago I got a CFT-1800 from a friend that had it for a number of years but stopped using it. The amp is in great condition and sounded well until this past weekend. I use the amp to drive a pair of Yamaha Mid-top cabs and as I said all was well. Last Saturday the amp was being used very lightly for music playback and had been running for about 2hrs when all of a sudden it started to crackle, pop and smoke. When I finally got it opened I noticed that the FET's (K1058) on one channel where pretty much baked. One of them was so bad that it had basically separated into two pieces. The other channel module appears to be in good order and I'm considering repairing the amp myself. First issue I have is I don't have a schematic for the CFT-1800 but have a request into Ashly. I explained the situation (via email) to the Ashly tech support folks and was told that I wouldn't be able to find replacements for the FET's. I suspect there are others on this forum that have repaired these amps before so thought I'd send out a note to see if I could get some help in sourcing parts for this amp. Including picture of one of the FETs. Thanks in advance for any assistance you could offer.