Hello all you knowledgeable people with nothing better to do. Maybe you can help me. I've got an Osaka Commercial 360mm f/6.8 lens in a Copal #3s shutter. I've had if for a while and kind of forgot about the thing. I can't remember what I paid for it now but it was dirt cheap. The lens had a ding in the barrel around the filter threads. I've repaired it so filters now screw on it like it was brand new.

I've done some research on the internet and some claim that Osaka Commercial is the same as the Commercial Congo. The problem I have is that a 360mm Commercial Congo came in a Copal #3 shutter and not the smaller #3s shutter as my Osaka Commercial. The 360 Commercial Congo has an image circle of 415mm. I'm wondering if the Osaka Commercial is the same. Both are Tessar lenses and said to be copies of the 14" Kodak Commercial Ektar. One thing said was that quality control wasn't the best so individual samples vary. Yeah, I know, I have to shoot it and find out for myself.

So I am wondering if it does indeed have an image circle of 415mm and if any of you know more information about this lens. Thank you all in advance.