Early Bleuet cards date from during WW1 though few seem to feature it. Card 65 is one example which does, including the baby theme, dated 1917. Cards with similar numbers were posted in 1915. Card 62 was printed by G Vie, Nanterre and card 65 by M Nicou, Clichy.
The Léo marque had belonged to the Agélous (see under JA or GA) before their death in 1921 - they were responsible for "the large number of nudes" commented on by the Metro postcard site. In fact Léo was still in the 1922 directory under GA (George Agélou). Lochard & Petitjean were not in that directory.
In the 1923 directory DÉDÉ appears as a marque of David & Co, together with the marque DB.
From 1924 or 1925 these marques belong to Lochard & Petitjean and feature attractive women, couples, children etc. Bleuet are usually monochrome with a lot of tinted cards - blue, sepia and even pink or purple. Dédé and Léo cards are coloured. By 1928 the company was just Lochard & Cie. Petitjean appears again later as the proprietor of Jaudel (qv). He had earlier appearered in the 1918 directory with a small entry, presumably as a seller of postcards.