Thanks for the comments. I have found conflicting info so thought a post here might help clear the fog.....
Mike, I think tightening the front screw pushes the gib to the rear of the machine, It appears to me that the adjustment washer pushes on the actual gib. At first I thought the opposite and that it came out the front. After cleaning some of the gook out of the adjustment holes it looks like the adjustment screws are just threading into the base assembly and the shoulder washers move the gib.