Well, we do have reasonable evidence that Paul Ysart told Colin Terris about making these badge weights. I would consider that as a reasonably reliable hearsay, but it does not tell us anything about the weight in question.
I also bought one of these a few years ago and at that time they were appearing with great frequency on eBay mostly from Scotland, too great a frequency for PY weights in my opinion. There is a dealer who has over the last 20+ years had made or altered a large number of items to misrepresent them as the work of the Ysart's. He has also sold work of various glassmakers as being Ysart. Miniature 'sample' glassware that were actually made in London, PY fake weights, altered Perthshire Paperweight Tulip lamps to sell as Vasart, ground down Strathearn seals and added a basal ring to pass of as Monart/Vasart, fake book of Monart colour recipes, several sets of Ysart family glass tools, other faked ephemera.
My weight does not seem right for PY compared to others, why would his standards have slipped for these? Other glass he made during the war and before the restart of Monart production did not show and slippage in his standards and by then paperweights were central to his choice of work.
I also find it highly unlikely that there was only one person doing this, during and at the end of the war there would have been economic chaos in many places across Europe and glassmakers needing to buy food. That Belgium has been raised with a stylistically similar example, combined with mentions of Belgium in relation to badge weights in the past, makes it a likely second source. Evidence could be concealed by language.
I would not be surprised if all of the following are true, but none proven.
1. Paul Ysart made some badge weights.
2. Other glassmakers in Europe made badge weights.
3. Somebody made a batch of badge weights in recent years.