A MIDI controlled modern band organ (Stinson for example) is generally
trouble free.  It will play chromatic modern music as well as classic
American and European music traditionally heard from band and
fairground organs.  It will need little attention and should it be
needed, maintenance is available through factory sponsored programs.
These organs can also include a roll tracker to play traditional band
organ rolls.  If your objective is to provide trouble free carousel
music on a routine basis, a MIDI controlled modern organ is the way
to go.

A collector would likely follow another approach.  Find out what kind
of organ (or organs) Silver Beach Park used with this carousel.  Also
find out what organs were used with other carousels of this lineage.
Then find an authentic original organ that matches this or similar
carousels.  Then try to buy it from the current owner.  Then have it
restored to new condition.  Then obtain rolls or books.  Then train
someone to operate and maintain it.  Also, put money aside for an
annual rebuild of whatever is broken.

I've done both.  A modern band organ is a sure thing.  It will just
play music when you flip the switch.  An authentic band organ is
a labor of love and compulsion.  If I were in charge of your project
I would probably locate a Wurlitzer 150 style roll organ and restore
it.  Probably a Wurlitzer 146 (or 153).  If I found a good 103 or 105
(125 style) I would grab it also.  It would take a minimum of about
two years to get one of these organs working properly.  To me, it would
be worth it.  The downside is that lots of specialized skills and
materials are needed to keep organs of this kind playing on a routine
basis.

On the other hand if I ran a park I'd go with a new Stinson 47M-2 MIDI
organ and just flip the switch every morning.  It would sound great and
require little attention.

Do you want authenticity or do you want a modern, trouble-free organ?
They will sound alike.  Modern is way more practical.  Authentic
provides a kind of satisfaction missing from modern, but with way more
headaches.

Bill Finch