First off, thank you for taking your personal free time to develop Duel Portal, both with Silverlight and now Unity. My highest respect too you.
Second, I noticed several people are a little impatient. So, here is an idea I had. Maybe just put up the new Unity version and scrap the silverlight card database entirely. Before the Silverlight version went down, there was a sea of cards that nobody used anymore, because the players left, or they were done with the deck. I myself deleted hundreds of my own cards I wasn't using anymore. Transferring the cards seems like you have to do it manually, so why not just have people just put the cards up that they need, no point in transferring hundreds, and I mean hundreds, of cards that nobody is using anymore.
I thought maybe this idea would save you time and work and also allow impatient people to use DP sooner.