if frame is an 08
your tires should be replaced as part of the deal period.
sitting for 3 or more years is just to much of a risk to your safety
we all know up-fitters and the like do not take the time to preserve the tires or even check inflation, so the course of safety would say imo to have then replaced
the batteries are imo under the same rule
my 08 sat for a year and they ended up replacing the batteries..because again it was plugged in at the dealer and no one ever checked teh water levels, so they were all but bone dry
titling it as a 2010 no big deal as your chassis and box warranty start at the time of sale, not when built.
USN Retired, Life time member of the DAV.
Enjoying the 2008 Damon Tuscany 4056, #3998 no your eyes are fine, there are really 6 slides
2022 F150 King Ranch or 2012 Edge toads