The error was on my part; I looked at the wrong focal length on the chart and misidentified my version as 159mm in the original posting (can't edit post #2 now).
The above illustration was taken from the 1914-1915 Wollensak Lens and Shutter catalog, but from reading around on the net, it appears there might have been poorly documented changes/evolution to the designs.
So the focal lengths for this 1914-1915 9.5 series are:
#3 -- 120.65mm for 5x7
#4 -- 127mm for Whole Plate
#5 -- 152.4mm for 8x10
#6 -- 203.2 for 10x12
#7 -- 228.6mm for 11x14
As stated, mine is in a Betax #2 shutter; I have seen other examples of the f9.5 in Betax #3 and larger shutters, but I don't remember or couldn't determine the focal length from the poor pictures.
As you state, you have the f12.5 version, which is a somewhat different from the f9.5 version I believe.
Anyway, it's an interesting early wide angle lens.
This image was taken with the 159.
Very nice image.