World Banknotes

Banque Nationale de Belgique, watermarked paper for 500 Francs (5), issue of 1910-25, glued into individual cream paper, black card or blue card frames, annotations on frames and paper, as produced, rare (5 papers)
BNB B533, Pick 72 £150-£200

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