1
general::
Phrase(s): none too something
not very something; not at all something. • The towels in the bathroom were none too clean. • It was none too warm in their house.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Also, not too. Not very, as in The application arrived none too soon, or I'm afraid this secretary is not too smart, or He was here not too long ago. The first usage was first recorded in 1885; the variant dates from about 1920. Also see NOT ALL THAT.
American Heritage Idioms