Madzo,

 there has been some book put out as a field reference guide/price guide  Classic Soda machines there are 3 edition
of this and it was by Jeff Walters the other is Vintage Coca
cola Machines  with a price guide and that is by Steve
Ebner.  That should get you started.

Steve 's address & phone number are here in the parts
area  And Jeff book is at Sodaware  if they still have any
left . I found  my first two at a used book store.
then I bought the 3rd edition .     '>