I don't know who did the work on your grips, but I have three knives that were scrimmed by Sandra Brady and she does wonderful work. Take a look at her web site at Scrimshaw By Sandra Brady - jewelry, knives, gun grips, fine art, pool cues, supplies, DVDs and images
She regularly comes to the Ohio Gun Collector's Association meetings near Wilmington, Ohio, the annual BLADE show in Atlanta and will be at the Colt Collector's Association convention in Norman, Oklahoma this year. She is also doing some work on accessories to be sold with the CCA annual auction gun.
If you can arrange to see Sandra Brady in person, take the grips with you. She may be able to identify the artist. I have a Randall knife with scrimshawed micarta handle signed "Curtis" that Sandy was able to help me identify.