Here are two fascinating ads from the First January 1958 Issue of Trade-A-Plane. I have quite a few old TAP's and will check others when I have time. (Maybe by 2020 or so!)
B-17F For Sale, R-1820-56 Engines, 14-Passengers!
This one has me guessing! It is a B-17F with a large cargo door and 14 seats, along with the 1350-HP, R1820-56 engines. I never heard of those engines being used on a B-17. Typically they are the 1200-HP, R1820-97.
I suspect it is 42-3470, for which you can see details on Goodall's list, page 3.. If you know more about this aircraft, send me some info and I’ll post it here along with your name, etc. This one by National Air Leasing Corp., Miami, FL.
TEN BOEING B-17G's, LOCATED IN ARIZONA
Here are ten B-17G's for sale in Arizona, $26,000 each! They were offered by Seale Aviation Supply, Love Field, Dallas, TX, and you could call, wire or write for more info. Nothing about email or fax! I wonder which B-17's these were and where they are today!