Info / manual for SOLIGOR 30D flash?

Today while hunting for vintage camera gear at a local flea market I ran across a very nice looking SOLIGOR 30D flash unit (for canon A1, AE-1...) it's packed with spiffy features and for $5 I had to have it.
Now I searched the internet high and low but no info or instructions are to be found. It's a nice flash and appears to be working fine. It does have some nonstandard controls I'd like to know what they're about.

any insight?

no luck as well, its a versatile flash. quite heavy though with four (AA) batteries

I looked at a photo of the panel. This is what I make out of it:

-) at the lower part you got the setting for camera-dedicated use. Chose either Olympus, Minolta/Pentax, Nikon, or Canon.

-) then chose either the automatic range A1 or A2 (just to exclude the manual mode)


-) for non-dedicated but auto-exposure set the filn speed at the finer scale above and either A1 or A2

-) for manual use just set M instaead of A1/A2. The flash goes off at full power

-) I'm puzzled by that 4-step fiilm speed setting.
I don't see the use of that. Though it reminds me of power settings used at similar lights for reducing output in the manual mode.