There are people who collect music boxes and band organs as
investments.  I contend that they are in the minority.  Most
are like me: they restore instruments because they love them.

As an example, I was recently asked the value of a fire engine
I own, a 1953 American LaFrance model 700 pumper.  My calculations
are as follows:

$ 4,000  cost of fire engine
    800  shipping to me
  8,000  mechanical work (brakes, transmission) to make it safe
  8,000  engine rebuild (12-cylinder Lycoming)

Value on today's market: $ 5,000
And I haven't even found a calliope to put on the hose deck, yet.

Marc Kaufman