I once lived in that area, actually in Auburn, Illinois, and I recall
that there was a gentleman with a collection near Berlin.  I believe
his name was Ringer.  This was about 20 years ago so I don't know if he
is still living there.  I remember that to get there I drove north from
the little town of New Berlin to the even smaller town of Berlin, then
I think it was a short distance west on the old highway running through
Berlin.

The setting was a small farmhouse with some outbuildings.  One of the
buildings to the west and behind the farmhouse was a large building,
as you describe, and many of the instruments were in it.  I hope this
helps.  I recall that when I asked about him in New Berlin they said
that he "marched to his own tune".

Howard Wyman