I take it they were not created on Auctiva.
Option 1 is to do the conversion on ebay I think there is a bulk edit type option there as they would be ended as SIF on conversion to auction.
Option 2 usually listings are imported automatically into Auctiva but there is a manual import option in the Auctiva closed listings page. Not sure whether they would need closing on ebay first though.
I would suggest you just try selecting import first and see what happens, nothing to lose.