According to the above site (should always be your first stop for all things B-17.

) on the page
http://aerovintage.com/RFC_B17.htm:
The First Group, Michigan Wing of the Civil Air Patrol received via RFC/WAA B-17G 43-39304 as a War memorial in 1946. It was sold to French service in 1949 and registered F-BDAT. Sadly, it crashed a few months later in Dec. 1949.
I find no other references to CAP receiving or purchasing a B-17. As CAP has always flown light aircraft, any B-17 under CAP's care would have been as above - a non-flying war memorial.