Just to close the loop on this: Both locos ended up going back to MTH for repair; the dealer who sold me the MEC Pacific referred me directly to Rich at MTH instead of taking it back for repair himself. At Rich's request, I sent both locos back to MTH; the repairs were not successful (diagnosis was loose flywheel for both) and one of the locos sustained more damage in transit coming back to me, so I returned them for the last time to Rich at the Springfield show last month.
One of the locos came from Mr. Muffin's, and they issued my refund within a matter of days of the return. Kudos to them for doing the right thing; they are a class act. I wish I could say the same thing about the other dealer, but I can't; I returned the MEC Pacific 4 weeks ago today, and still don't have my refund.
