@silvaire1: What a beautiful example of a fantastic aircraft - you're a very lucky person! I learned to fly with Flugsportgruppe Bölkow in D-EBOI (c/n 102) which at that time was painted in the same colour scheme. We had another one as well, namely D-EBOE, and were based on Neubiberg airfield (now closed), close to Ottobrunn. Both of them are pictured in the book you cite above. D-EBOI was originally in a white/blue/black scheme, and can also be seen in that scheme in the Monsun formation picture on the Flugzeugunion Süd internet link.
Incidentally, the Monsun was initially developed as the MHK-101 as a private initiative by a Bölkow employee, Hermann Mylius, and contains some design features of the Bölkow Bo 208 Junior produced by the company at that time (the boxy rear fuselage and the all-flying tailplane). The original MHK-101 survived until very recently and was destroyed in a fatal crash. He also built two examples of a very similarly looking single-seat aerobatic aircraft, the Mylius Tornado. Many years later, his son attempted to return both of them to production, but the company went broke before they actually built any. Apparently, Messerschmitt-Bölkow-Blohm made (almost) no profit on the aircraft they sold, and decided to focus on helicopters instead.