Didn't know if you would get back that far in the messages Jeremy, so wanted to bring this forward for you to see. My reply to your respons:
Thank you Jeremy for your response as well. Most appreciated. No, I'm afraid I'm NOT looking at insulation. No insulation ANYWHERE under the house between the dirt floor of the crawl space to, nor between, the floor joists up against the old tongue & groove floor/sub floor. Just from wood to dirt and all air inbetween. I'm going to assume that when/after I put my new floor down, I should be insulating underneath? And if so...what type (R-rating) should I be using?