Anyone heard of the famous "Francois Pierre"?
Yes. John Hawley had heard of him
and included a brief entry on page 30 of his "B&S & NEGC" book, and said that "styles attributed to him included ... blown fruit".
On my very limited experience, I would agree that the shape of the base of the eBay Pear suggests SL rather than NEGC. But then I have only ever got close to two SL blown fruits (both Apples) that I photographed at the PCC Exhibtion in 1999 - one of which had a base in exactly the same form as the eBay one. There was also an NEGC Pear shown in that Exhibition, which had a round base, just like the few shown in the book.