hi rik

i probably won't be of any help here,
but when i solarize in the darkroom
i have a red filter i can put infront of my enlarger
( so i could line it up again with the negative in the
enlarger + the print in an easel.)
i had a system where i would pull the print, wash it a little bit
to remove excess developer, put it back on under the enlarger
and re-expose the paper that way. i used to do this when i had
areas that wouldnt burn very well, and this worked very well ...
(spent/dark ansco130 works wonders for this sort of thing) ...

good luck!