Dave, as usual, your timing and wisdom are perfect.
I am not a gauge R&R specialist, but was hoping someone was going to come along and look at this data.
Sorry for being late to the thread, and the ethics comments previously were excellent. I just wanted to add: before you get too upset with your management, make sure your numbers and study are accurate. Whatever happens in the future, the better your study and numbers, the less difficult your situation is.
One thing that popped into my head is whether there is any significant differences among shifts. I might perform ANOVA on these three groups to see if there is significance. If there is, maybe some additional training or something is in order to minimize variance among the groups.
If I were you, I would spend some time and determine where the variance is coming from to see if it can be remedied. If it can't, your managers are never going to understand your contributions through R&R analysis. You probably want to find a job where you are better appreciated.