Auditing
I hope I am not teaching granny to suck eggs here, but all the checklists that you download are not a lot of use to you. They may give you some ideas but you must not lose sight of the fact that auditing a base is for the purpose of ensuring that they are operating to the company procedures as laid out in your manuals. Therefore your starting point is the manuals and you should prepare an audit guide from them.
In my time as an auditor, I found that checklists were helpful but too restrictive if followed too assiduously. You need the ability to follow a trail to get the best from an audit.
Checklists from the CAA or similar are fine if you are auditing the manuals to determine that the manuals comply with regulations, but the checklists for that purpose need to be updated for each audit of the manual.