FWIW…
I have a friend in Burbank that specializes in vintage video formats. He can transfer just about any old format, 2″ Quad, 1/2″ reel to reel, U-matte and so on, to a newer format for preservation. A while ago he sent me an article about a procedure for saving a tape in poor condition, usually due to failing or deteriorating binders. It involved literally baking the tape before transfering it to a newer format. I don’t have the article any more but you can contact David through his web site at:
dcvideo.com
Might be worth a try to save that old tape.
Tell him I said “Hi”.
Tom