Brian,
All you need is the last three digits of the code, 819. Call a local locksmith and ask them if they can cut the key for you. Normally they have access to the codes but sometimes they may not have blanks. There was a guy on the forum recently who got keys cut at a hardware store, so you never know.
As stated before, the tank cover will work with just about any Honda key. Also FYI, the ignition switch has a chrome front, which extends down the sides of the switch barrel. It takes some work to get at it but way down there in a small font is a similar code, and again it's the last three digits that are what's needed.
Of course, it always best to take the lock with you if you can.