Dennis-
There are several discussion about key blanks and where to source them on the Member side of the forum, I would be happy to provide a link but as a guest you would not have access.
Since you recently replaced the ignition switch, I am also unsure which key blank is right for your plane.
If you provide more information about your switch, perhaps one of us can point you in the right direction, you may also consider upgrading to a full Member and finding the answer directly on the forums, sounds like you would make back your Member dues on this one piece of advice alone.