When carrying out 'Check Out's it is always good practice, if the previous paperwork is not already loaded into KMS or a copy in the library tab, to request this from the client.
You will be able to request this by pressing the 'Notifications' tab which you will find in the subheading tab on a job, and then the 'Send Client Paperwork Reminder' this will send an email directly to the client contact, who is attached to the specific job asking them to attach any previous paperwork they have to the library tab on the job.