Here's some more. Hopefully you can see by these pictures that this condition has gone on for quite a while. The home has supplies from the ceiling from attic AH. The return runs 20' across the attic, down and outside wall to crawl then a return trunk the length of the house. There are perimeter returns with baseboard registers, fed from panned joists, some with runs tapped off them for other registers.
She said she has always had humidity problems and couldn't get the house warm when she visited during winter, (2nd home at the beach). She said she was told it was her systems were so old. No one, to her knowledge has ever looked in the crawlspace and certainly never mention what I showed her pics of. She agreed not to say anything about my visit and what I found. She has 5t in an approx. 2000 sq. ft. home.