Been lying a long time and had leaked brake fluid ruining the the servo.
First piston /seals came out no problem but the second was nightmare. Had to block all the holes and shove an airline down it.
Looked very dodgy (rust, scored) so thinking I had nothing to lose, scotchbrited it.
Came up a treat as it appears only the zinc plating was goosed.
Tried the old piston/seals and seems to be tight.
Luckily I had an original Ford overhaul kit in the cupboard.

My question is since I have taken of the plating, how do I stop this from rusting internally? Thought of being liberal with Red grease beyond the first piston and in between the two and after.
It's a 90 car still running abs and sourcing a new master cylinder looks to be like looking for hens teeth.