Hi Peter,
Paperweights with encased military badges on coloured chips were certainly made by Paul Ysart (most likely in the 1930s) but he was not the only one to do this. Belgium is believed to be at least one other source.
There is actually no fool-proof method of confirming the maker of weights like this. They were individual personal keepsake items rather than regular production pieces.
However, yours seems to show gold aventurine amongst the coloured chips and this is a good sign that it may well have been made by Paul Ysart. A photo of the base, to show how it is finished would provide other clues. Does the glass dome appear to be "dark" or "grey", rather than very clear? If so, that could also fit for an Ysart item from that period.