Peter Von Brackel, in his 1999 book, Paperweights, Historicism, Art Nouveau, Art Deco, 1842 to Present
shows several similar style weights in pages 40 & 41. They all have the same look, with brightly coloured canes over multi-colour "bits" and a central white plaque. He suggested they were from Thuringia and early 20th century.
So yes, on that evidence I would have said the eBay example was of the same source and period. The 1845 plaque may be unusual but everything about the weight ties in with the others in the book.
It is possible that weights with a "souvenir" type plaque were made on request and that dated examples could have been asked for as a commemoration or similar.
And maybe, if there were enough of those produced (even if we have not seen many in modern times), they could have been an influence for the mid-20th century "false dated" examples from Murano. But that, of course, is just speculation with no evidence - but it's intesting that the date plaque in the eBay weight is very similar to those in the Murano ones.