Therer was one unit of MS 406's in the Levant as of March 1940, however at this stage I can find no evidence of the type being present in April 1941.
The french did not view kindly the failure of the Morane over France in 1940, and were not keen to incorporate it into the post-armistice air force. severely restricted in size, it appears that the major fighter elements of the Vichy air force were the D 520s, H-75s and MB 152s that had survived. There is also some evidence of some post armistice D 520s and MB 155s being received by the Vichy air force
The air fighting over the Levant is nevertheless interesting. The French fielded 279 aircraft for this campaign, including 35 D 520s, and an indeterminate number of Martin 167s. At first they did quite well, but RAAF 3 sqn also acquitted itself pretty well, flying P-40B Tomahawks (I think it was B)
Tomahawks of No. 3 Squadron, Royal Australian Air Force (RAAF), took part in the first attack on June 8, helping to destroy a Dewoitine D.520 fighter and damage three others at Rayak airfield. Elsewhere on that same day, two of No. 250 Squadron's Tomahawks drew first blood for the P-40 in the air when they shot down an Italian Cant Z.1007bis reconnaissance plane five miles northwest of Alexandria, Egypt. The Vichy French put up a spirited fight before finally signing an armistice on July 14, but the Tomahawks of No. 3 Squadron RAAF also acquitted themselves well, holding their own against France's top-of-the-line D.520s and shooting down two out of eight German Junkers Ju-88As of II Gruppe, Lehrgeschwader 1, operating from Crete, that tried to interfere with British landings on the Levantine coast on June 12.