I remember reading somewhere that you have an 90% chance of a Thul or lower drop in Hell, 9% of Amn - Shael and 1% of anything above that, with a Fal or Lem being the highest she'll drop. These might not be 100% accurate, but from my experience in doing Countess runs, they seem to be fairly accurate. So your chance of finding high runes or finding mid-runes to transmute into higher runes are slim. But then again, you always have the chance of getting a Terror Key from her, so it's not all bad.
I've several games lately with people needing Pul's, so be patient and you can probably trade it up. Um has a chance too, but Dol is too low to do much of anything with.
Not sure on the helm and ring...