Mystery 10.5" F/8 convertible lens

I'm designing a full-plate camera and while looking through a box of old lenses I might use on it, I stumbled across an unkown lens I've had in storage. It is a brass-barreled lens in a brass Wollensak Regno shutter and appears to be a symmetrical (?) and convertible lens. The aperture scale is marked in what I believe is the old US system as the sequence goes from f/8 to f/16 to f/32... The focal lengths listed on the shutter are 10.5", 17.5" and 23.5" and I see three reflections in the front as well as rear element groups, two are bright and a third smaller one. There are no markings on the lens.

Any idea what I have here? I'm thinking maybe it is an early 6.5 x 8.5 Voltas F/8 based on this page from a 1919 Wollensak catalog:

http://www.cameraeccentric.com/html/info/wollensakcata/voltas.html

TIA for any info.

Joe

I think you have almost the same lens that I have, but mine is 10 3/4", 18" and 23 1/2" . Mine is marked Rapid Convertible 6 1/2 x 8 1/2. I have been in touch with Seth at cameraeccentric, but we couldn't really determine what it is. It may well be a Volta, but then it's strange that it's marked as "Rapid Convertible"?

Oh yes - mine is also in a Regno shutter and the apertures marked in US.

Poor picture, but I had it ready