But independent of what means might have been used to rename the files, inside or outside of LR, LR will not see tow files of differing names as duplicates of one another. Your best strategy, as I see it, is ti Synchronize, import all files of differencing names but files which are likely to represent the same image; apply some dummy keyword and color label at the time of importation that allows you to find the new imports later on, and then sort according to capture time. Unless capture time has also been changed, in which case you are hosed, the dupe will live next to its original file. The color label will be a visual cue to the files you're like to want top get rid of, but virtue of its being a duplication (of differing name) of the file you wish to keep.
John Beardsworth, and possibly a few others, may have better suggestions that prove my offering here to be more clunky the needed.
I've been where you are. It's a nuisance. The bright side is that it's only a few hundred files...
John Caldwell
