I have been updating my guitar finishing thread daily, but neglecting this one. Just in case it helps others, I am going to add this update to my progress. I am still working on finishing the body and neck before I move on to the final build. Here is my progress so far.
Here are pictures of the posterboard mask I made. I used screws to lift it 1/4in above the guitar body to allow for the burst. I sprayed down and slightly toward the middle of the guitar to get the overspray into the gap in the mask. It came out better than I expected. I used encore brown lacquer from Mohawk to get the look.
Not bad so far!