Just came across this picture in another thread, which may give a clue as to the frame's origin. Apparently
this The Dura, a brand of mr A. Declercq of Roeselare, used the same decals. Declercq was a frame manufacturer, who owned quite a few brand names of his own, but I strongly suspect he also supplied unbranded frames to others, as many Belgian fame builders did. Those frames usually came fully finished, and just needed the new owners headbadge and name on the down tube. If this "AA" is indeed the painter's decal, than it might well have been on the frame before it was supplied to Visser.
