Think you should have just let the master key flash once (before the 3 flashes) before moving to the new key. Could be the issue.

Hello mate , have you solve this problem? I am also stuck with trouble. Hoping you could provide a feedback.

Hi, the ignition switch you have assembled has got the metal tube that is welded to the frame of the Vespa. Do you have the part number for that tube or can you tell me where you got it?