No strap on main awning. How do I know the length I need?

I have no idea what kind of awning it is. I'm literally learning as I go. I ordered one that is 94.5", which seemed to be the longest. I figured a little longer couldn't hurt. I went and looked in all the storage bins all around and inside the coach and could not even find the pull rod, so I ordered one of those as well.

This is going to be quite an adventure. I knew it would be, but that's okay. It's an '85 and there are going to be lots of little SNAFU's.