The information in Scottish Paperweights was accurate according to the knowledge at that time. However, we must take account of the fact that the weights believed to be by Eisner are simply a copy of what he would have known (and presumably made) in Czechoslovakia before moving to the UK. And that style of weight, with both plain coloured and striped petals, also conntiuned into modern European output.
So far I have never seen any "Eisner" weight that has a translucent and well-formed pot. What is a common feature of the ones I have seen is that some of the petals have, on the underside, a neat grid of tiny air bubbles, presumably formed by nodules in a tool used to shape the petal. The example in the eBay listing does not have the grid feature - just random and variable sized bubbles.
Of the few "Eisner" weights I have seen with striped petals, none have been as clean and tidy as the example in the eBay listing. The "Eisner" ones often have dark "patches" on the upper side of the petals, and this also applies to plain coloured petals, too.
In truth, I don't know the date ranges of the European flower weights of this type but the colours, pot form, and general tidyness make me think they are not too old.