The MIM (Musical Instruments Museum) in Brussels is well worth a visit:
http://www.mim.be/en
Its wind collection contains some 125 instruments made by different members of the Sax clan, including a series of saxophones, a wide range of saxhorns, saxotrombas, cornets, trumpets, instruments with six valves and seven bells, omnitonic and valve horns, bugles, flutes, clarinets, etc. It is one of the largest collections of Sax instruments held in a public collection.