Man!
You guys rock!
Thank you, thank you, thank you for all the great replies.
I did as suggested and brushed off that non-drive dropout and sure enough it's stamped Campagnolo along with a serial number.
The serial number is 245221.
Pics below:
Does this particular drive side hanger mean I need to run a particular derailleur like a certain Huret?
Outside non-drive view with serial numbers and Campagnolo stamp.
Inside non-drive view.
Inside view.
Outside view.