Good afternoon everyone, I've already fixed the pulley by replacing the gasket and timing belt. It was a great relief to discover that there was no damage to the valves, as planenut had already told me. Thanks to the website
www.m3wservices.com, which supplied me with several parts. I also fixed the speedometer with the part from Bunny, who also got me a pulley. We managed to get the correct torque on the pulley bolts thanks to the instructions in this chat.
Many thanks to everyone for helping keep these wonderful machines running.