OP here. As I noted in my original post, Dicor has three different products, TPO, EDPM and Brite TEK which is TPO with the fleece on the back.
I looked today, and my existing roof is black on the back side, indicating it is EDPM, which simply means that Thor obtained it cheaper than anything else, don't know that it is better or worse. The roof material is OK but the leak at the TV antenna was the problem. The sheathing on the roof is OSB, not Luan and it looks like I will be replacing the first 4 ft section on the right side. It doesn't look like it got into the sloped front wall from what I can see initially, I will need to pull some more staples and peel back the top sheet of metal on the front to get a complete look.
I will get it opened up next week and will know more. Just finished removing the LH side retainer and the front retainer today. Front retainer was heavily covered with butyl and I figured it was better to scrape it with it attached to something rather than trying to hold it in my hands and scrape it clean. Still have a lot of cleaning on the strips however. Need to get new filler plastic for the retainers, and new screws. Also have to locate a number of small items such as gutter spouts (old ones crumbled).
Thankfully I am working from a extended platform scissor lift. Took my Android tablet with me up the lift and watched/mostly listened to Youtube videos all day, makes the day go better.
I was just trying to get a better idea of which way to go with the material system.
Charles