OK first things first, you need to find a new dealer.
Were talking with the parts guys or the service department?
The heads may fit but not entirely sure , but the carbs will not without a machined adapter plate.
The non Venture type Royal stars made from 1996 to 2001 used 28mm carbs, the Venture type Royal Stars made from 1999 to 2013, which include the 2005 to 2010 Tour Deluxe use 32 mm carbs.
Having said that, I know some folks have converted non-Venture Royals to accept Venture type carbs, so it can be done, but requires a decent machinist, new carb boots and changes to the air box or air filter, I think most that did it used single pod air filters on each 32mm carb instead of using the air box set up Yamaha uses.
If no one here chimes in with more specific information, go over to the DELPHI forums for Royal Stars and Ventures, I know there are some folks over there that did it for sure.