There is a well known glassmaking family of Tosi in Murano.
However I'm not convinced that's Tosi at the beginning of that long number, it could be the start of the number as the 's' looks more like a 5 and 'o' could be a zero etc. If we could verify the 'T' better it would help, but I can't see it from the photo.
Also how is the pontil mark finished? It looks a little rough/uneven from the photo.