Miata offset crankshaft keys

[ITABoy]

My IT-A Miata coming along very well. I've run it in two races with pretty fair results for an old guy. Having lots of fun and that's what's is all about, along with the technical challenges.

On later subject, I milled my head according to the IT max spec and would like to correct my cam timing. The SCCA allows this operation with an offset crankshaft key. The big problem is that I can't seem to find any available. Do these things have to be special made or is there a source???