Does anybody know the cost to upgrade a Version I Mini Torii to a current UFO model? To my knowledge this involved changing capacitors, adding feedback adjustment, and replacing the standard transformers with UFO transformers.

The product page states that the adjustable feedback was included in the October 2012 version. What month was yours manufactured? If it was close to October the feedback could have been included. If not, yours was probably returned to the factory for this update. You should see what kind of capacitors it has. It may need just the UFO update.