Importing & merging previously exported time-series data

I have a CSV exported TimeSeries data using `tb-rest-client` running on Python. I want this data re-added to an existing device on a new Thingsboard instance that had to be re-initialized due to some file system corruption we had. What is a good way to merge my current data with the past data so I can visualize everything in Thingsboard's GUI again? 
@rretanubun