Sorry for being slow with the image...life got in the way of play.
The actual size of the head on my homemade seal driver is 1/4 inch thick and 2 3/8 diameter, but it doesn't have to be exact. The only important measurements are that it can fit through the inside diameter of the bearing, and that it is thin enough to fit between the inner bearing and the seal.
I also took a picture of the pliers that I have used to remove the large snap ring. They are some ancient crusty pliers that every once in a while find a purpose. Notice the longer than normal handle length. Perhaps if you welded some "handle extensions" on a cheap set of modern pliers you could get the leverage needed to compress the snap ring. There is limited work area inside that hub.
Are your wheel bearings the Hyatt barrel style cup and cone bearings? Even though your trucks and mine are only a couple of years in age different, there seems to be a lot of technological changes in those years.
