As Paul only signed for personal visitors, there is an extremely low possibility of a signed piece being sold without an accurate description and history.
If only it were that simple! There are quite a few examples of script-signed P. Ysart weights that have been through the market place at least twice. These do not necessarily retain the "descrption and history" by the time of the second selling.
As yet, the eBay weight referred to is the first I have seen which is obviously wrong. Apart from the look of the signature, the weight is simply not an Ysart piece of work. I, too, have no idea who actually made the weight.
Of the genuine script "P. Ysart" signatures I have seen on weights and bottles, most are very similar but some look a bit different. I have four examples in my collection and one shows a very "wobbly" signature, but the weight is ok, and is certainly from the 1970s period. I suspect that Paul signed that weight when he was quite elderly and his hand (let alone his eyesight) was not as good as it used to be. All of those four signatures can be seen in my web pages.
A specific point about the wrong signature on the eBay weight is that there are certain elements that do not match the genuine ones - even my "wobbly" one. And this is, so far, true of all the other genuine examples I have seen. So, if anybody fancies copying the signatures based on my web page images, they really should study them very
carefully to get every aspect correct. But even then, without hours and hours of practice, it is unlikely that a copier will get it right with the proper flowing style that Paul used.
With this info in mind, if any GMB member finds a script-signed "P Ysart" item, post a photo (if you can get one - the sigs are not always easy to capture) and I can certainly check it for the specific details.