Not all clasics are needed to be inspected, according to Avherald
The FAA released Emergency Airworthiness Directive EAD 2011-08-51 requiring all Boeing 737-300, -400 and -500, line numbers 2553-3132 (delivered between 1993 and 2000) to be inspected
http://www.avherald.com/h?article=43a83ca1&opt=0and a poster on that site says "AD Effectivity
just to clarify, the AD is not applicable to ALL 733, 734 & 735, it only affect Line Numbers 2553 to 3132. Earlier Line Nos up to 2552 were already covered by FAA AD 2003-08-15"