*UPDATE*
Just wanted to close this thread out and report that the manufacturer, Gulfstream, has shipped me three replacement tires + wheels directly to my doorstep. I received them today.
They are the correct size this time, made by the same manufacturer Hi Run and are ST205/75D14 LQ229's. They are rated at 1760 pounds each, which will safely support my loaded rig.
Taking into consideration that the wrong size and weight rating lasted as long as they did while being used, unbeknownst to me, completely overloaded, I expect the new ones to perform quite well! That said, I'm thankful that the odds favored me & my family and we didn't experience a critical failure (which could of resulted in death). I implore everyone looking to purchase a new rig to always check these things out before walking off the lot.
Cheers
*edit: for the record, these tires are sold at Walmart - with wheels - for just $85 a piece! Pretty cheap:
http://www.walmart.com/ip/Hi-Run-ST-Bias-Boat-Trailer-Tire-with-Wheel-Assembly-ST205-75D14-6-Ply-5L-Tire-Only/23573686
