It's probably a doujindance based on the power adapter, mono audio cable, and the whiteness of the console. Is there a silver toggle switch under the Hucard door?
The best thing you could do is open it and take pictures as was mentioned. The problem is selling a mystery modded duo r on a forum where we are all into these.
Anyone that buys this will immediately want someone to look at it. So they will take that into consideration when making offers to you.