Extracting all data from vault prior to Office 365 migration

We are going to remove the EMC SourceOne system and we want to export all the data from it, because management want to migrate to Office 365.   I'm re-inflating live users.  In AD we have all the original user accounts, but when people left the company their email account was deleted.

There are a couple of thousand disabled account (people who have left) with no corresponding email address.  Their data is in the EMC SourceOne vault.   We need to export it, at least back to something like a PST, in preparation for the decommissioning of SourceOne and migrating all data to Office 365.

The normal process would be to get the canonical name from the database.

1. "select * from DataSource where FriendlyName like '%'" to get them all.

2. We would then work through the list, using Discovery Manager, and recovering all email and using the canonical name as the owner (that seems to be how EMC like to do it). 

3. Then export it to PST.

But we may have 2,000 to do, so how can we automate this?  What APIs / command line tools are available to automate this, in vbScript or Powershell perhaps.

I asked EMC but technical support said they weren't able to help, and suggested Professional Services, but I'm reluctant to tell management they need to fork out a large sum of money to get the email back.  In Program Files (x86)\EMC SourceOne\Worker\Bin I can see what look like application tools which would carry out specific tasks, e.g. Archive, Delete, Query, Restore, ShortCut, etc.  If you run them you get nothing, and trying /H /? -H -? doesn't give any command-line options.  I guess they are used by the EMC process.   Is there any documentation on these, or APIs / library routines, or does anyone know how to automated this process?

btw, we're using 6.8, so not the latest.  Any merit in upgrading to the latest versions of the SourceOne software - are there new features which make this easy / easier ?

thanks,
Jonathan