I made some prints recently on Polywarmtone paper, I didn't allow enough for the dry d own density increase, they looked great wet and after Selenium toning. However once dry shadows had,blocked up.
Before r-printing I thought I'd see what could be done to save them. I bleached them in a strong Ferricyanide/Bromide bleach and washed them well, I was left with just the reddish Selenium image. In artificial light I redeveloped the prints slowly in warmtone print developer at 1+19 rather than the usual 1+9 placing them in stop bath once the correct densities had been achieved, followed by the usual two bath fix, wash etc.
It worked far better than I'd expected, I now have two excellent prints, it's worth a try
Ian