Have an old Errtee Brass lens and I cannot find any info on it.

This is the only image I have found that has the lens on it. The right one.

https://www.pinterest.com/pin/292734044505655185/

There were thousands of lens manufacturers at that era , your photographs would tell how was that lenses engineering . Or try to find german magazines from that time or contact with Ian Smith , he might give you some information.

jsatterthwaite said:

This is the only image I have found that has the lens on it. The right one.

https://www.pinterest.com/pin/292734044505655185/

Click to expand...

you might consider posting the same question on largeformatphotography.info in their forums section
there are people that know LOTS about old european brass lenses and most likely will know about yours.