I like that mod - it identifies the missing files and allows normal coppermine code to process the deletes - doing all the needed cleanup...
The downside is if there are a lot of albums - or albums with more than 100 files (the max you can display in edit at once) - will need to repeat the process once or more on each... (maybe can adjust that max - at least on vps server shouldn't be a resource issue...)
Assuming it could be refit - would need you to 'Edit Files', set display to 100 files, and 'Apply Changes'... The pics with missing images will already be selected to delete... (If more than 100 files - I would start at end of album and work backwards...)
Would this work for you?
What version/release of CPG are you running?
Can you provide a link to the gallery so I can see what it looks like?
Plugins (or mods, code changes, etc) start with an idea...