Garrett seems to be a busy person, I often send him email’s with questions, and he always gets back to me… be patient.
yep! he emailed me back the day after 
You can, but we really don’t recommend it. Their tuning is very sensitive and to make the horns sound in harmony, they need to be tuned precisely.
So, although it can be done, I recommend leaving it to us. (and not adjusting the tuning from their original setting at all)
yeah, garrett said they can tune the horns, or they can only replace the bells…