The smart ass kisses you
. Just kiddin' (at least I am just kidding, you doesn't seem).
Yes, your question was
Can you tell which files are missing?...
And the response is : all is detailled in the mod install descriptions.
Really, all is explained in the author notes : quoted from part 1, also present in each part:
## o Part 1 is common to all versions
## o Part 2 is required if you haven't Split topic type v2 installed
## o Part 3 is required if you haven't Categories hierarchy v 2.0.4 or greater
## o Part 4 is required if you have Categories hierarchy v 2.0.4 or greater
## o users can choose their prefered setup (required full mods settings mod to be installed).
## Admin can also choose to override the users choice for each setup parameter.
Really, I don't know how to explain this better : I assume you know at least what mods you have already installed on your board. If no, I strongly advice you to first do the inventory of them, and possibly restarting from scratch with a clean phpBB and reinstall known stuff only.