Body and paint . . . here we come

Before I can have my bike painted, a couple items need to be addressed.  I need have the horncaste repaired where the horn grille mounts.  Note the photos below.  I found a brass (maybe wood screws) holding the horn grille on.  I tried to back the screws out with a Sears stripped screw remover.  No luck.  No budge.  Therefore, I began to drill out the screws, but stopped after the heads fell off.  I stopped to ask LCUSA members and my paint shop the best way to approach.

 Drill, tap, chase seems to be the best way to determine the damage.  It is challenging to replace a horn caste for the early TV, with the chrome ring.

Other than this, the horn caste is in good shape I believe.