The Notes section of TCDS A696 states that all except the seaplane BC series planes are eligible for the left wing aux tank installation. I have a BL model and the A700 does not include this , mentioning only the fuselage tank behind the seat. My DAR wants me to copy the 337 pages used by any one of us who has a BL or BC which later was fitted with a wing tank. Looking for N Numbers of those planes so I can order the CD with the Form 337 approvals. This is another of those paperwork roadblocks on what really is a safety improvement. We have to prove that adding the additional 6 gallons in a factory made wing tank will not cause the plane to plummet from the sky and into an orphanage. Many thanks for your assistance! Bob C