Thanks folks.
@afremont, I read though the sparkfun article and data-sheet, and I think I understand the RS-232 and TTL differences now, and can appreciate your reasoning and why you suggested what you suggested. I think, I do have some MAX232x's somewhere and can use those.
@fungus, are you suggesting that I hook-up the TTL-level Tx pin, to the dongle/converter's RS-232 level Rx pin, and "try it out" ? Nothing bad can happen, because Rx-end can, in worst case expect higher voltage signals (and perhaps, also inversion). At worst, this thing won't work, but usually no fear of magic-smoke! Right ? Or, I didn't understand your last statement.