If this is indexing v2 then you have the index for all the jobs in the media agent. So browsing for the time period with the show deleted option selected should be able to show the deleted objects.
If this is indexinv v1 and if the index of the jobs in the aux copy is available then we would be able to browse the data with show deleted option for the larger time period and this would provide you the deleted objects during that time period. If the index is not available then in that case we need to get the media used during that time period using the list media option so that index could be restored and we would be able to show which objects that were deleted during that time period. you can also keep the index on a different location for longer retention periods so that we dont need to recall the media in these cases.
documentation link to keep the index for longer retention for indexing v1 :
Please escalate this in case you need any further help on this.