You will probably wait a long time - there is not really a generic replacement, per se.
It would be faster, and perhaps even better, to have one made if you can't make one yourself (increase the transformer rating, use faster rectifiers, new filter caps, etc.). I've made and upgraded several - one for my Forte and several for my Threshold gear.
The design is simple - a toroidal transformer, dual-rail supply that is only rectified and filtered in the chassis - the voltage regulation occurs in the preamp box. There is the typical Pass ground breaker approach, the only tricky thing is the Misumi circular plug on these is difficult to find these days. My approach (if I didn't have 2 extras on hand) would be to switch to a different circular plug on the captive cable, and corresponding jack on the new PS chassis.
Can't find a picture of mine, but this is what they look like inside.
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