Who is I.M. or L.M.?

At the time when this card was written the city name was Constantinople. Why Atatürk renamed the city?

Encoded "Get Well..." Message from Constantin Astori

C.Astori worked as an art restorer for Smithsonian Institution and Cooper-Hewitt Design Museum. In 1940 he was commissioned to paint a mural (flying reptiles) for American Natural Museum in New York. This mural is still over the stairs in the museum. Later in 1970 this mural was used in the album cover of Dinosaur Swamps by the band called the Flock (band). He participated in various art shows but never realized his dream of becoming a famous artist. His art work can be found in private collections and art dealers internationally.
Here is a "Get Well..." card from Mr. Astori to his friend written in an encrypted form (Rebus). Try to decrypt it!