Michael,
On reflection, I think the pieces are designed by Scarpa. Techniques and designs were mixed at Venini. For example, a piece that was designed as a bollicine would also be produced as pulegoso. Also, I did find a couple of examples of white a bollicine pieces from 1932-3. The shape from yours is from the sommersi series, 1934-36. Although the pieces were designed in those years, they continued to be produced for years, often one shape using the shape from one line with the technique from another line. The acid stamp is also strong evidence for Scarpa as it was used 1935-45.
Wayne's piece is similar to your piece, but bullicante rather than a bollicine. The pieces in the book aren't shown with pestles, btw, but I'm sure they could have been added. Scarpa wasn't against functionality, after all.
My suggestion would be to contact Venini, who I've found to be remarkably helpful. I mentioned in one post that on my last visit to Murano I spent an afternoon in the store talking about glass with a sales assistant. She pulled out some special pieces for me and produced some reference material, even after I made it clear I wasn't buying anything. When I left the store, she even shook my hand and thanked me for coming in.
Here's a piece of mine that is a similar shape to your piece but from the sommersi series. The acid-etched mark is from 1930-1945.
Once again, great find!
David