I have a 1946 140, most ADs have been long ago taken care of. I have attached a copy of the AD list for mine that we use at Annual. As far as known areas of concern, the fabric is attached to the ribs with clips, if the wing holds water these will corrode. The first indication is a bulge and crunchy sounds when you press on the location, the the clip fails and the fabric is no longer attached to the ribs in this location. The struts are subject to an AD due to internal corrosion, if the one you are looking at has sealed newer struts then this one no longer applies. Pay attention to the pins that hold the seat back in place. The top pins get seen a lot, the lower pins are seldom seen except maybe at annual. Being fabric covered, most are stored inside so corrosion should be minimal. As far as the fabric, remove an inspection panel and take a decently bright flashlight and hold it up to the fabric from the outside just over the inspection panel. You shouldn't be able to see the light if you look up into the inspection hole. UV kills fabric, if the installer applied enough silver the fabric should be protected. If not, it won't last many years if left in the sun. Unprotected fabric will lose 80% of its strength if left exposed to sunlight, even indirectly, for just one year.
Any more questions, send me an email.
Kevin Alderman, A&P/IA.
