First off WOW! What a wealth of info! I really really appreciate it.
Sounds like it is worth it to pull the motor and tear here completely down. I am going to have to dig around for some sort of service manual.
So 13.13 carb, Dr43 plus matching heads, Gianelli stock+ pipe as it's less offense, ported and matched and possible variable speed upgrade.
My Ciao's are most definitely single speeds. Ill start digging around a d finding info on how to do the swap.
Here are some pics below, you can see I have some tank repairs to do on one as the previous owner but out some small rusty areas. I have a Vespa mechanic friend that does restorations on vespas and says it's possible to fix. We will see! If not I'll try to find a donor frame.