Vintage Belgian NOS New Steel Randonneur Touring Frame Set – 55cm - Flandria?

Description

Vintage Belgian NOS New Steel Randonneur Touring Frame Set – 55cm.
Includes uncut matching fork.
Built in custom rear rack.
Hand painted and pin striped frame.
Measurements:
Top tube – 57cm – cc
Seat tube – 54.5cm – cc / 56.5cm – c top
Spacing – 100 – 115
Seatpost – 26.8
Threading - British
I purchased this from a seller in Belgium but have not built it up.
Note there are no manufacturer stickers on the frame.
From research the manufacturer is likely Flandria, and their Randonneur frame set.
Additional Information:
I have added 4 additional pictures showing the underside of the bottom bracket, rear drop outs, head tube and fork to show there are no original manufacturer stamps or notations.   The Head Tube lug has "BCM" stamped on it, which indicates the lugs were manufactured by Bocama Lugs, a French company.   The steerer tube on the fork is stamped "Nervor", an another French company that made steerer tubes and forks.   It appears this was a blank Frameset that were sometimes made by Belgian and Dutch manufacturers so that others, like bike shops, could add their own decals. Still think the Frameset was most likely made by Flandria based upon comparing photos on the internet with their Randonneur models from the 1980s.