Contrary to the initial writeup,
I believe the plural of "True" should still be "True," as it's short for "True One-Ounce Pieces of Gold", rather than "Trues" or, worse yet, "Truths."
Well, if he's Raklin "The True" Diamoniar, wouldn't they still be "True" in the plural, or at least "Trues,"?
So, True, Trues and Truthes are all correct (and no, that's not a negotiable point ).