From where I sit, I can't see the K-28s every surviving the RGS's poor trackage in it's later days.
However, if the RGS had survived w/a bit more capital available and better maintenance, and if those K-28s hadn't gone to Alaska, then i think this could've happened. The RGS was looking for more motive power even in it's weakened state. Had it been strong (dreaming, I know...) and K-28s were available, I bet they would've tried 'em.
But we know the end of this story - terrible track conditions, no money, and no K-28s available. Still, it's nice to dream now and then.