Jean Riboud, the French billionaire and industrialist, who married the maternal niece of Somendranath Tagore was one such visitor. Riboud was introduced to Kumar, by R.P.Gupta, not to forget that many of the people who found their way to this quaint address was introduced by him. Whenever Riboud visited his in-laws place, which was near Entally market at 161, Lower Circular Road, and opposite to Kumars, he made it a point to visit Kumar. In his Kurta, he very easily slid into the mileue and spend his time pouring over books, many of them in French, which Kumar got from Chandanagore, the erstwhile French colony in Bengal. Riboud loved to eat a Bengali starter, called “shukta”, which had no equivalent to any cuisine of any other countries. It was a concoction of bitter gourd and sweet potatoes, among a host of other ingredients. Jean made it his specialty and compared it with the taste of 'Campari'.
Alongside Krishna Riboud, Jean would hunt for rare books on Indian and Chinese textile, for that was her long loved subject of research. They were drawn to collecting works by Surrealists and Indian progressives – Max Ernst, Joan Miro, Yves Tanguy, M.F. Husain and J. Swaminathan (none of them had then become famous). They were enthusiastic supporters of the French and Italian new wave in Cinema and were instrumental in assisting Henri Langlois establish the Cinemateque Francaise.