I just picked up a High Hand and it looks to be in a similar condition that yours was.
Therefore, I'll be going back over the thread again now that it's more relevant to me :)

Quick question on the air brush paint.
I have tried using the createx opaque range but find that I have to do a lot of coats to get good coverage and I get a noticeable edge after I remove the mask.
Also the colour doesn't really cover darken areas that well. Do you put down a white base first or is it that the paint I'm using doesn't provide a solid enough colour?
I'm new to air brushing so sorry if it's a basic question