All legal 337's will be on file with the FAA, you get them on the CD with the registration and other file paperwork, when you request the records CD for a specific airplane, thru the FAA website.
http://registry.faa.gov/aircraft.aspDepends on how the log books were reconstructed. Of course, there would have to be log entries for each and every AD, and the ones prior to the missing logs would have to be entered and signed off with method of compliance, etc.
Many times there will be a letter, signed and notarized by one or more persons attesting to the hours on the airframe and engine. Sometimes supporting documents are used such as 337's filed that give airframe total time, or shop work orders, or other verifiable documents.
Charles
