Different from Imperial's catalog 400, F-6785T (Bib no. 54776).
Mount Vernon ware includes pressed goblets, ice teas, salad plates, sherbets, butter tups, pickle dish, bowls, bon bons, Lily bowl, plate, celery tray, candy box with cover, sugar and cream set, cake plate, shallow nappy, square relish, comport, vase, berry bowl, salt and pepper set, ice jug, salad set, candleholders and 3-toed bowl. Nucut ware includes a two handled comport, berry bowl, handled nappy, sugar and cream set, salad bowl, vases, footed jelly, celery tray, handled pickle, pickle boat, partitioned nut dish and more.
Catalog is not dated, suggested range of dates derived from trademark on p.  of cover. This trademark was approved August 1921 and was used through the late 1920s.
Appears that when cover was cropped, an additional numbere followed Catalog no. 40, and appears to be another 0, making this catalog no. 400.