Comprehensive review of the following:
Airframe, Engine, APU Logbooks for completeness
Airworthiness Directives
Mandatory/Alert Service Bulletins
Life Limited and Overhaul Requirements - Airframe, Engine, APU
FAA Form 337 - STCs, Instructions for Continued Airworthiness and AFM Supplements
Equipment/Supplemental Equipment Lists
Damage History
Flammability Requirements per CFR 25.853(a) & 25.853(c)
Inspection status (AWL and Chapter 5)