Well, I am feeling much better about my learning curve and Fred's new roof.
I spent the last couple of day's lunch hour removing the structure from the donor roof off of the brown turd. I managed to get all of the old structure removed, while leaving the rain gutters attached. Looking at Fred's gutters, most of the right side was toast. I thought about it for a few days and decided if I could prep the donor roof like my brain saw it, I would then be able to take a sawzall or a cut off wheel on the angle grinder (my new best friend on this part of the project) and zip the gutters off Fred at the outside edge, leaving the entire original lip.
So I laid the new roof in place for an initial look. I believe it will work just as I imagine it will. Next move will be to mark the existing gutters for the 1st cut, zip them off and set the new lid back in place for a final trim of both the new roof and existing Fred gutters. Once we get it where we feel real good about it, Josh will flap-disc the underside of the roof and spray it with a rubberized undercoating. I figure that will keep some of the "tinny" sound of the sheet metal to a minimum. Then it will be final edge prep/clean of both the roof and of Fred, and panel bond this puppy together, not forgetting to caulk/bond the middle cross brace to the new skin in the process.
I truly do feel a whole lot better about the whole thing now.... WHEW!!!
Oh, and Fred has a flat tire. The dry rotted right rear has finally lost it's ability to hold air for longer than 12 hours... go figure.