You can get all the IDs using yt-dlp
yt-dlp --flat-playlist --print id <playlist>
Assuming you're on linux, you can add >> ids_all.txt
at the end to save the list to a file.
You can also add
--compat-options no-youtube-unavailable-videos
to get only the list of available videos instead and then, again assuming you're on linux, do
diff ids_all.txt ids_available.txt
to get the odd ones out. That's the simplest I could come up with. You'll have to hope you can use the wayback machine, or a good old exact search to turn up what video that ID actually referred to