Curious if the Synchro shifter is working OK on this bike.
The Synchro shifter system is notorious for not working for most people because of the slap dash indexing engineering that Campy did for the component to try and catch up with Shimano's SIS indexed system. Bad shifting can really get in the way of enjoying this bike and may even affect its value.
One can always replace the Synchro indexed shift levers with not indexed equivalents from Campagnolo if indexing cannot he made to work reliably......or just permanently turn off the indexing by lifting and turning the knurled ring at the present RD lever, permanently.
The 1st gen Chorus RD should shift very well just on non-indexed, friction mode.