Scooterotica

What are the symptoms of a worn or damaged cruciform on a Vespa gearbox?
Can it cause difficulty in changing gear?

usually slipping out of gear (3rd tends to be worst)

With difficulty in changing gear i'd be looking at cables, clutch and selector box,

In my experience it's usually clutch

Agreed with above, if it were me i'd check the selector parts before you open up to look at clutch.
Selector box top off, check cables, then whip the selector box off check its all okay, then the rod that connects selector arm to cruciform.

Good luck

How old is the scoter ?? Occasionally a new selector box with stiffer springs and sharper cut selector arm wheel was all it took (after id already replaced the cruciform doh!!)