Bartlett blades, I have used copper pins many times and haven't had the issues you are asking about--having said that I have not used them in Ivory Micarta--I've used them on Coffeee bag Micarta, Burgundy linen Micarta, Black paper Micarta, and Blue paper Micarta--on these I have had no issues with the copper pins bleeding or staining the Micarta in any way. I would say if it was a concern to me, I would take a small piece of the cocerned Micarta, and mount a pin in it, and finish the pieced as I would a finished handle scale to see if it's an issue.
Best luck to you -- looks like it will be a nice knife!