Try reducing the hole rather than broadening the mandrel.
Do you have a washer or similar with a 1" OD you could tape in place then suitable smaller mandrel [or similar] in the router?
Or you could wrap electricians tape around the rim of a spent 12 bore cartridge which I believe is ~ 22mm, the...
FWIW for the last decade we've visited Rome more or less annually. We take ~£500 in euros and usually bring some back, I tend to pay for most meals etc. by card, I've had no trouble using visa or Mastercard, including Visa debit; they've been accepted just about everywhere.
I may be missing a jape here but you can of course post to any named individual at any address you like. It will go to that address and the physical recipient would/should then make sure it ends up with the correct recipient, if different.
One of the comments on that vid. suggests shimming/packing the side of the speed adjustment pot. might 'fix' the problem, however a dodgy potentiometer is not good. This machine has a three year warranty, how long have you had it?