World Banknotes

Banque Nationale de Belgique, watermarked paper for 500 Francs (6), issue of 1910-25, glued into individual blue card frames, annotations on frames and paper, as produced, rare (6 papers)
BNB B533, Pick 72 £180-£220

It is very likely that this paper dates from the 1919 issue, which was probably the first date printed in England rather than Belgium