Brake Servo

Hi All , I have noticed a damp area around the ridge of the servo and although the van has not been on the road as yet , I wondered if they are also prone to servo leaks , I can see that the fluid is eating away at the paint   so it has to be brake fluid although my fingers are crossed that its just a bit of over spill from when I topped up the reservoir . If the worst comes , are they difficult to replace and whats the best source of replacement ,and cost please . Hoping Matt or Woody may have a spare if needed . ( Fingers crossed ) .  

Cheers All

Eddie