Oops! Inadvertently sent that before I was done.
The two photos on the bottom right show him tuning a Pro-37. He has a microphone attached to a tuner, a shim, and what appears to be an engraving tool he’s using on the reed. Is the device an engraver? We can see that he’s pinging the reed with his shim. Engraving pens usually cost about $10-20.
I have a friend who is a dental technician. I’ll try to remember to talk with her about melodica tuning. I think the dentist’s office would be a good place for it. Their devices are air powered and have a foot control.