Too bad there isn't a standard for barrel wall measurements provided by dealers and auction houses. Would sure be helpful to make meaningful determinations on barrel condition. As you point out, the MWT number is better than nothing, but doesn't mean much when you get down to brass tacks.
MWT of .040" sounds great in an advertisement...unless it happens to be at the end of the chamber.
I can't help but wonder. Is this lack of information intentional? Or, have buyers just not been educated enough to ask, therefore creating the demand/expectation for the data?