I started learning about harmonium repair recently from a friend. The harmonium is essentially a miniature pump organ, so not very similar to a piano at all, but a lot of the same repair techniques apply. Even though it is more of a wind instrument it is still an antiquated mechanical devise put together with wood, leather, felt and bits of metal.

This is a photo of the harmonium case (right) and removed keyboard (left) in the shop looking over Kootenay Lake with the mountains across the water hidden in clouds (as is the case for 90% of the winter, sadly).