How did you do that?
I would like to do the same thing - using an older backup on an external HDD for restoring the bulk of all files and using a newer (more current) backup on a remote storage location.
The problem I see here is that just doing a restore of the older backup first and then using the newer backup for updating and adding files will leave files in the restored location that were deleted or moved in the time between the older and the newer backup. So, it wouldn’t be an exact reproduction of the latest state.