Posting this in the hopes that it helps the next bloke who is trying to get a spare Piaggio sidewinder laser cut key made in the US...
If you don't know already, the Piaggio BV350 and some other scooters use a laser cut "sidewinder" key, different from your traditional bladed key. If you buy a blank spare key and need to get it cut, ideally you'd go to your local locksmith and they could just look up the model and cut it for you right? Wrong! I went to so many local locksmiths and they all turned me down saying the scooter wasn't showing up in their database.
I researched this forum and people recommended shipping my original key out to shops in Cali or Texas. I heard great things about both places, but I personally was uncomfortable sending my only remaining master key in the mail in case it got lost.
Some posters on here were really helpful and said if I mentioned "Fiat" to a locksmith, they could figure it out. What finally unlocked it for me was when Buckeye Marksman posted this PDF: https://www.laserkeyproducts.com/files/Greg%20Brandt%20High%20Security%20Chart.pdf
and pointed me to p10.
So I took this to my local locksmith, and he used key code "DE02489" to cut my key after looking up the Fiat and the key code in the PDF.
Just programmed my new key according to the manual, scooter starts up perfectly, and best thing is I didn't have to mail my original key anywhere!