Question about replacement power supply

Hello, I recently lost the plug-in half of my power supply (the part that goes into the wall) and came here to see about getting another power supply to replace it.  I narrowed down which one I need, which happens to be  As is mentioned on there, it is not currently in stock.  Because this is a relatively older model MyBook, does anyone know if it will be back in stock, or is it more or less discontinued or rarely put in inventory?  Are there any other avenues I can go about getting a replacement if necessary?  Thanks!

As long as the adapter has the same specifications you can get any generic brand at any electronic store.