If they are mostly yellowed, I would pull them out of the pile and let them finish coloring up on a string and then dry them. They should be ok if you hang them in the garage or basement to finish. I say this because I know how tricky pile curing can be. They can go bad (mold) at this stage in no time in a pile if you don't watch them very carefully.
I don't have any info on CT157, but it sounds like a good strain. I would like to grow it to see how it does here. I would take the frost resistant claim with a grain of salt though. I have grown over 300 strains and only found one I would truly call frost resistant. I have found a few that can take an hour or so below freezing, but my rule is pick it before I lose it. Frozen leaf sucks.
This is all I can find on K326. Sounds like one I should add to my grow list nest season.
"K326 is a flu cured (bright leaf) strain developed in the early 1980's by Novartis Seeds by crossings of McNair 225//McNair 30/NC 95 "
Delgold I know well and have grown it a couple times now. http://nwtseeds.com/DelGold.htm
"Delgold is a superior flue-cured tobacco cultivar developed at the Agriculture Canada Research Station, Delhi, Ontario in 1980 by crossing Babor Rustica with two popular American varieties, Hicks Broadleaf and Virginia 115. The result is a high-yielding flu cured cultivar with a nicotine content of 2.2%.
Delgold is one of the best known bright leaf varieties and still considered one of the better yielding flue-cured varieties available for commercial tobacco production. It is fast growing reaching 5-6 feet in height, and produces large, wide, heavy grade light green leaves. Matures in 70-75 days."