Your detailed post is greatly appreciated! I ordered two of these for the flipper buttons.
The monitor bezel has been finished. I bought plexiglass from hobbylobby. Using the following steps, I prepped the outline for spraypainting:
1. Cut the plexiglass to the size of the entire front face.
2. With the piece pressed onto the front of the LCD screen, I taped off along the outside of the clear opening with masking tape (frog tape).
3. Flipped the plexiglass over and used the outline of the tape to tape off the inside portion of the clear opening, extending the tape further than necessary.
4. Used a boxcutter/ exactoknife to lightly cut the excess tape (without cutting through and scratching plexiglass) around the clear opening area. Then I teared the tape along the cut lines.
5. Lightly sanded the non-clear area with 220 sand paper.
6. Spray painted with indoor/outdoor black paint.
I did a couple coats within 5 minutes of each other and then pulled the tape off right away. Before pulling the tape off, I took a peek at the other side to make sure all spots were painted. The paint dried very quickly.