Yes sorry, Tim. I should have mentioned that the 25.5VDC is the
open-circuit voltage across the caps.
I assume this new drop is do-able because this PSU in its original
configuration provided 24VDC regulated from 40VDC unreg across the
caps. That seemed like a hell of a drop without generating heaps of
heat, but I freely admit my recollection of linear PSU design (like a
lot of other electronics-related stuff) is very, very hazy.