I, too, loved that book as a kid...and I don't think the Steve Martin movie has anything to do with the book...personally.
I haven't seen either, but it's clear Steve Martin is NOT doing a cover of the actual life of the industrial engineer.
His "cover" of "Out-of-Towners" was a joke, too. While it can't be said to be as divergent as "CBTD", it was way divergent in details.
And the REAL "Out-of-Towners" is hysterical!