I do understand, that shops earn more money by selling new bikes than servicing old ones. However it`s a sad story.
Numerous engine parts are interchangeable between Paso, Sport, Supersport, Monster or even Cagiva Elefant.
Good Duc mechanics should know this, not only by experience but also by their trainings. I know from my Mechanic that he`s in Italy at least once a year when Ducati invites for such events.
But as you say lot of shops don`t really care. They don`t know the bike therefore they cannot help or don`t want to. If they would take the time to check things they would see what other parts could eventually be fitted.
My engine is full of parts from newer Ducs. The crankshaft was from a Monster, the flywheel is for Supersport/Monster as are the aftermarket cylinders, carbs came from a Supersport/Monster also. The axles of the valve rocker arms were changed from the old type to the newer one with the clip etc, etc.
I really hope you`ll find a shop (and may it not be a Duc shop) with some passion and time to help you out.
btw. I think I still have an original fiche somewhere if you need it.
At least I do recall I had one for the Sport and 906 (or 907ie ?!) I don`t even have a fiche reader. It was just a collector`s item

)
Gerhard