So I discovered that the two screws that hold the seat latch have fallen away. They are according to the Vespa parts list part # 575249
It looks like this https://www.sip-scootershop.com/en/products/screw+m6x16+mm+_pi575249
In one of the listings it is a M6 x22mm screw and in another instance it is a M6x16mm screw.
But in either case it happens to have a collar/shoulder.
When you order two screws and they are $149 each plus S&H it becomes a ridiculous price and I was hoping I could find it at the local hardware store.
But not sure about the size or whether Id find M6 screws with a collar at a HomeDepot.
NYC sucks this way in terms of machine shops that sell to individuals for reasonable prices.
McMaster would have something like this I am guessing but again it will be a question of do I want spend almost $10 for 2 screws?
For now zip ties are doing the job.