Filter by name for "Version 2", give those all a color label, clear the filter, make sure your Browser Metadata overlay is showing color labels, and sort?
Then "9" each of the images you want to delete.
Then either "Show all" or filter for just rejected images, review, and then send 'em to the trash.
Also useful might be to narrow the first search by excluding images which have adjustments added. Or limit to a date range that includes the time of the accidental duplication?
Lots of ways to narrow, mark, group, & sort.