Bought a 2004 but Find Out It's a 2003

Should I be concerned?

Would you be concerned, if what the RVT ad showed and what I was told by the seller before I made the purchase, was different than what is confirmed by the VIN number on the title today?

A few weeks ago I posted on an RV forum that I was looking at a 2004 Coachmen and was looking for any kind of feedback on a 5.7L engine and that RV traveling in the western states. I was then told by the seller it was a 6.0L engine, which would make a difference in buying replacement/repair parts, possibly performance. From that forum post from a couple of weeks ago, I confirmed today that I have a 2003 Coachmen with a 5.7L engine instead of a 2004 Coachmen with a 6.0L as advertised. The 8th digit from the left on the VIN shows R, which is a 5.7L. Not until 2004 did they change to the 6.0L based on information that came from two GM Tech's. The local GM mechanic told me about the 8th digit from the right of the VIN shows it was a 2002 chassis earlier this week.

So, should I be bothered that a small list of things the RVT ad showed as well as what the seller told me before the purchase is confirmed to be different that I have bought? Or, am I just on the paranoid side for buying a used RV?

As far as the oil cooling line replacement, I plan on starting Saturday morning early unless there is heavy rain and lightning. The forecast shows only a 40% chance of thunderstorms tomorrow and 50% chance of thunderstorms on Sunday.  I am anxious to see if the connectors are what I think they are instead of what I am told. That will mean no tool for my guess or using a connector tool on theirs.