Reprints From A Belgian Philatelic Exhibition

Hi all,

I have these 4 blocks with reprints, which were issued at some Belgian Stamp Exhibitiohn:





The problem is that I cannot find any references to those blocks in my various stamp catalogues, or even online. I do not know which exhibition (year, name) issued those blocks.

Can anybody shed some light on the name of the exhibition, the catalogue numbers of the blocks (if any) or patential value?

I will aprreciate any insights.

Adam

Hi.
Most likely from Belgica72
https://www.delcampe.net/fr/collect...6658391.html

Thank you vayolene!