No worries, we've all been there, done that!
To my knowledge, the stainless grip frames that never got the lock are all XR3-RED size that were already in production when the lock was introduced. Ruger only made grip frame casting moulds with lock accomodation for:
1. the new XR3 size grip frames, both blue and stainless (for the New Vaq and flat top Blackhawks), and
2. new moulds for the blue alloy XR3-RED size grip frames.