If we're getting away from allowing factory catalog items as OEM parts then I would like to see hammers added to D4 21 as a minor component. I don't see the hammer as any more major than a safety.

I, like many others, have the competition hammer on my SP01, it came that way from the Custom Shop. I have no interest in changing it and if it is deemed illegal I will simply not shoot production any more.

If pistols that were allowed at National and Area matches last year are illegal now I have no interest in playing. What's to say it won't be something else next year.

The SP-01 Shadow is a custom shop gun that is on the approved production list. Based on the interpretation of 21.6 " Parts from “custom shop” guns will only be considered “OEM parts” if the custom-shop gun is on the NROI list of approved Production guns." the competition hammer is considered an OEM part.
This means that the competition hammer would be legal on any of the SP-01 and 75 models based on this statement of the NROI: "3/09 INTERPRETATION - EXTERNAL parts: components which are externally visible may ONLY be replaced with OEM parts which are offered on the specific model of gun, another approved gun from the same manufacturer except as specifically clarified below"