My local hardware store, Ayers, in Arlington, VA came up with this. I asked for the Curtis B56. I gave him the original Royal Enfield key. He said the B56 wasn't close. Maybe I got that tip from the wrong section here. I have a 2004 with an electric start.
This key is an ilco, X54 DC1 and it works! So if you need a blank and didn't order one from CMW you can find one of these.