I believe 121 companies are only required to provide records that are within the 5 year look back from the date requested

The original post indicates part 91 and log book is gone so I would assume it was an 8710 event .
but 8710's will show re examinations if say the instrument rating or cfi check ride were failed for example . 8710's are there forever AFAIK .

The logbook being missing / destroyed may illicit more scrutiny.
Being honest and forthright is is the only way to go whatever the case .