I wish I had better news for you, but from a safety perspective, it would be wise to simply replace all the Mission tires with a US-made tire. From my research, it is much better to be safe and absorb the cost than to risk damage or injury. If possible, save and store the old tires in case an opportunity for a rebate or refund becomes a reality.
I strongly suggest RVers everywhere contact the Recreation Vehicle Safety and Education Foundation (RVSEF) to inquire about their coach weighing schedule and other weight and safety educational products. RVSEF is the only independent facility fully endorsed by RVIA and RVDA. Visit them at: www.rvsafety.com.