@Stig, good you ride on "angels", best insurance ever.
But what I don't understand, what is those "Brand" dealers argumentation, not to work on a Piaggio?
Not that I would trust them with my scoot and let 'em work on it.
Here in Italy they would not even wink, and take you in.
And, BTW, I paid a couple of months ago for mounting, balancing and disposal of my old tyre €15,- incl. VAT. Wheel brought into workshop by me.