I was told, through the assistance of another boardmember who I'm not sure has arrived here as yet, that this machine dates roughly to 1920, that the vesper company itself was in existence for only a short while from 1918/19 to 1922 at the latest... there are two identifying decals beneath the lid in the playing area... vesper refers to the phonograph company, stadmac refers to the furniture company that manufactured the cabinets...
the other neat thing is the design itself, if you notice, the lid opens from one side of the cabinet, but the horn is on the opposite side... similar to the victor revere (which used the floor) or the Pathé reflex models or decca trench portables (both of which had bowls in the lids into which the sound was directed before reflected out into the world), this machine was designed to be placed in a corner of the room, with the horn facing the wall, off of which the sound would have been properly amplified...
below are copies of an ad for this machine, a jacobean table model with the table on which it was intended to sit... and a price list showing the original cost, as well as another ad showing information on the reproducer and tonearm...
