A good locksmith can make the key for you from the keycode. In fact, keys made that way are better than ones made using the common key copy machine found in most hardware stores.
And, despite what the ebay ad says, there is an all metal blank available, albeit, without the yamaha logo or black plastic head. There's a thread here somewhere that has the correct blank (non-Yamaha) part number.
edit. From my spare key. ILCO X248 YM63
edit2: Ilco ym63, Taylor X 248, Curtis yn 63, Silca yh35r.