Fibreglass problem

A couple years after painting this car in the late 90's, blisters
started to appear on the DS fender. The problem got so bad that the car
was sidelined until recently, when it was decided to try and remedy the
paint problem.
After the shop stripped the paint, and wiped it down, a stain
started to appear where the blisters were. It was determined that this
stain is silicone brake fluid wicking it's way into the fender.

The area in question has been treated with Prep-sol, to no avail. The
next level was an aircraft quality silicone remover, which does ok on
the surface, but the stains bleed back up after a couple hours. There is
also another product, we used, that is supposed to penetrate, combine
with and remove silicone, but it appears to have 'energized' the stuff
and now, it's spreading further.

The origin was obviously the master cylinder and the fluid has wicked
it's way around to the front of the car now
Anyone have any suggestions as to what approach to take on removing
this stuff from the panels, so it can be painted. Is there anything you
can use, over it, to seal it in?

Replacement of the panels isn't an option.

Any advice wiould be greatly appreciated... Mine is "never use silicone
brake fluid"

thanks