It was in 1963 he won the Munich prize. (He was 30 years old in 1963, when he was asked to become a member of the jury in the "Internationalen Wettbewerb in München". He then discovered that he could take part in the competition and he did and won the first prize.)
This (after 1963) was the start of his solo-career.
His wife was pushing him. MA was happy being an orchestral musician. He played in major French orchestras such as Philharmonique del la R.T.F (the Paris Radio Orchestra) (1953 -1962), Orchestre des Concerts Lamoureux. (1953 -1960), and the orchestra of the Opéra-Comique in Paris (1962 -1967). He also played in smaller more jazz-oriented groups.
From 63 to 66 he kind of built himself as a soloist. He also was the trumpet star with Karl Richter in these years (doing a lof of Bach's works).
Good timing also in regards to recording (the LP format)
Ole