Rps3 I feel your pain. For probably half my life we fixed everything outside in the snow, mud, rain and hot sun. I am so fortunate to have a nice shop to work in. This project is going to have to move along though cause it can't stay in here for long.
I made a cardboard template of the rafters and marked it out on plywood. I went to my neighbors and used his bandsaw to cut them out. He was in the mood for company so I had to visit with him for a bit.
I notched out the sisters for wire and drilled holes for bolts. Also made some spacers for where rafters were rotted away. I glued, bolted and clamped the scabbed sisters to the rafters. 3 down 3 to go in this area. I have a bad spot in the front to. I think what happened was that previous owners changed fabric on awning and attached rafters for it in different spot leaving old hole open. Once a little moisture gets in it's like D.C. Said it never dries then OSB soaks it up membrane becomes lose and starts to flap wearing holes and well you know. I didn't get quite as far as I wanted to but still made pretty good progress and have a working plan. All in all I'm happy
Bjrogg