You should be able to open the original or previous versions of the file from the History folder. Then you can save this file as anything you want.
By the way, how are you feeling about you/your company's decision to use Quicksilver?
We find it to be a major PITA. Lately, we are seeing about a 15% chance that all of the property data fields are blank even though we have a paper print showing that they were there at one time.
I see that they haven't been shown on Solidworks partner list for some time.