Thanks for the input, motoman. My point is, Briggs & Stratton spelled out the cleaning process in particular detail, and it was followed to the letter. They call the pull rope and related sheet metal a "finger guard", and it is highlighted in diagram #19, page 4. There is not one mention that it need be removed, so as to clean this area, and I ran my old engine for 20 years without ever removing and cleaning the finger guard. I'll take the service dealer's word for the fact that the thing was clogged---I have not seen it, and don't think it could be all that bad. I don't think the interior of that area being clogged would account for the overheat---I think there was problem with the valve adjustment, and after about 12 hours, the engine failed. The air filter and all exterior cooling fins were totally clean, especially all little nooks and crannies on the exterior of the engine.
If the matter goes to small claims, I will definitely be asking for punitive damage. You're right---I could be mowing. And I don't mow for appearance, but rather managing extreme fire hazard. In my area, there is no fire department to call, and in times past I've seen an 8' high wall of fire send 15' cedars up in fireballs. Bad news is, it's starting to dry out, and I'm surrounded by 5' johnson grass, and no engine.