G. Gennert New York Lumen Seraph The Lens Combination 3x4 to 25x30 7 Achromatic

Description

The two ad pictures are from the 1895 G.Gennert catalog.  The first ad top right is the Seraph, then the Lumen is the second ad, left.  This will describe what it is and the combinations.  This set is complete with the lenses marked with the 15 and 25 on the lens and then 35, 45, 55, 65, and 75.  The glass is good and the aperture ring turns well.  Very rare and not much reference out there.  The thread diameter looks to be about 36mm? of the elements and the barrel thread about 42mm?, 1 5/8"? It is not the M42 thread.  The lens measures 45mm with the front and rear elements attached.  The aperture rings read 0, 1, 2 ,3, 4, 5.  This is about all I know about this set.  Feel free to offer any insight.