Aye, new to Moto Morini 350's so I may have more to contribute as ownership progresses!
Removed the right-hand outer case to have a wee look see at the timing belt and decided that some brake/clutch cleaner wouldn't go amiss where the starter shoes grip. A previous owner has already pock-marked it, with a centre puch.

Having cleaned things up, it became very apparent that the starter motor feed cable had been worn away by the drive chain!

It would appear if care isn't taken when replacing the casing and then zip tying the cable, with tension from the starter motor terminal, it will tangle with the drive chain. So, clean up with brake/clutch cleaner and then seal off with heat shrink tube, then some braided cable cover tidied up at each end with more shrink tube.
Also the filler plug on the starter motor gearbox is missing!

The threaded cross-head oil level screw is in place. Please would someone tell me what the filler plug is made from and is it threaded?

It appears that it could be a rubber plug with no threading, but some info from more experienced owners would be welcome.
Thank you, Bill