It's amazing how much it creeps under healthy looking paint. I recently painted the RallyKa, and ended up bare metalling loads of it to get out the rust, even though it looked fine before I started.
What made you go for that over the New G25/35 range from Garrett? Pulsar also do them. Everyone is raving about the G range
got to say loving your build so far. feel like doing mine aswell? lol. Don't have the know-how to do it myself to the extent you have gone wish I did.