moving assets off of S3

After some research, it appears that the assets being pulled from S3 are on an S3 account owned by a previous (and now defunct) company. They are not stored on my client's S3 account. Apparently, for the time being, that S3 account is still active and allowing my client's site to access those assets. However, my client reports that, because the previous company no longer is open for business, they have no way to reconnect with the previous company nor to log in to this S3 account.

[A] Is there a way to pull the assets from the current S3 account (for which we do not have login access) back into the web server?

[B] Could you tell me what db table contains info as to which items are on S3 instead of on the local server? I would like to query the db to see how many items are out there, and to know when I have everything. I know that only some images/documents are on that S3 account while others are still on the server, so I assume there is someway that the web pages know whether to reference either S3 or the local server.

[C] For what it is worth, people previous to me have pushed some images to two other S3 buckets on the client's S3 account. Because EasySocial expects only one bucket, some links are broken. Do you have any recommendation for how to merge all of these assets into one location (be that the local server or on S3 bucket)?