After several days of research , and more hours than I care to think about, I can now tell more about than I thought possible about Maison Agnes.
I have contributed a fuller write up of Maison Agnes to the Vintage Fashion Guild, and it will go up soon on the VFG Label Resource. But until them, I can clear up several points about this fashion house. It was not affiliated with Agnes, the milliner. It did not open in 1906, but was covered in the US papers as early as 1898. There was an actual Mme. Agnes. She seems to have retired/died/been bought out by 1909, when Mme. Havet is shown as the Directrice, with her name on the label. She held this position she until 1941. The house, with Mme. Havet at the head, merged with Drecoll in 1931. It did remain open during the WW II occupation. Mention of Maison Agnes-Drecoll ends in 1952 in L'Officiel. Some internet sources say the house remained open until 1962, but I find nothing to back that up at this time.
Maison Agnes was a successful and well known house, and was popular with American buyers, but was not of the top tier of Parisian houses. Their strong suit was more along the lines of 'taste' than innovation.
" A formal wrap of embroidered black canton with bloused bodice and prominent side fastening. The fine soutache embroidery pattern with scalloped edge is worked in white on lack and an alternating use of black on white, bands the sleeves. Jet nailheads form a narrow design on the cuffs. A fine pleated edge finishes the standing collar and cuffs. Embroidery pattern No. 110"