It turned out our diagnosis of blown turbo-charger was correct; I think we'll have the truck back by maybe noon tomorrow. Rough cost: $2100, actually that is kinda rough, not chump change.
I've no notion why the check engine light didn't come on, it seems to me it should. Not that anybody towing trailer wouldn't instantly be aware of the power loss the first hill they came upon - it is that dramatic.
Tomorrow afternoon we drive to Jackpot, a NV town on the Idaho border 40 miles south of Twin Falls, ID. Virtually all of NV is on Pacific Time except Jackpot, which is on Mountain Time along with all of adjacent ID and nearby WY, from whence their customers come.