Exactly,

Gotta be careful not to push down hard on the knife, its also got to be super sharp.
This works for large areas like this,
 But when i come to do the blue parts with the lettering inside, its a much longer process done over several applications.
Your paint thickness has to be spot on also - too thin and large amounts of leeching occur, too thick and it wont atomize properly.

Also taking off the mask, needs to be done at just the right point of the colours setting. No hard rules here, depends on climate you are working in and also your mix of paints. i find a combination of white spirit and thinners works best.

Im always in 2 minds when i restore a PF - id rather not do it, original is always best. But with the amount of loose and flaking paint on this, the machine would pretty much be unplayable without slowly destroying the PF artwork.
 I see no point in having all original scuffed up museum pieces in the collection that cant be played, so sometimes the choice to restore is made. So long as the job is done well, it wont detract from the value of the machine.
Ive got machines in my collection that have had "professional"restores on them - i look at the work and just shake my head knowing it could have been done much better. Thats my opinion.
 But then again, im a bit anal about this type of thing and like to do ALL the work myself