Concorde probably NOT, yes I'd agree (BUT the brand DID get applied to some rather strange offerings just for the Benelux market that never were exported to the US, etc. including some lower-level Asian-sourced frames).
I sure do not recognize these lugs but they are unique so somebody might, and the NDS DO looks like it may have been "modified" (ground down a bit).
My gut reaction is that it's some mid-grade...could be Asian or Euro...I'll be watching this to learn.