I couldn't resist buying this, even without being able to find out much about it. The cells I have are marked 305 and 390. Combined they seem to be around 190mm or so. Is anyone familiar with this set? The individual cells seem to have decent coverage- at least 400mm. Together they seem to cover (or light up) around 325mm or so.

The aperture scale is interesting. At first I thought the aperture ring was threaded backwards as the scale seems reversed (the marking '47' is indexed to wide open and '4' is stopped down) but after checking the iris with calipers the aperture markings appear to correspond to the diameter in mm.

I'm looking forward to using it to find out more about it, but if anyone has any info on this set I'd be interested in hearing it. Thanks.