Now I got the paint off (mostly) it seems to me that the lugs are not bilaminates but ordinary lugs just filed down. Triggering a radical re-think about it.
Here is a pic of the lugs and fork crown denuded of the paint:
What do you think?
I think it is a nice period tourer frame.
Maybe a small maker but still of interest.
The fork crowns are distinctive, even if I don't know what they are, yet.