IMO the secret to having a grip with an eagle or other raised design, e.g., stars, etc., is to have the design on the finger side (outside side). For example, if you're right handed the design should be on the right side of the grip. IMO it gives a better purchase. With an eagle on both sides the grip feels too fat IMO, kind of "Rugerish".
Pappy, IMO the most common designs on ivory stocked guns of the 1870's were smooth (Colt factory installed), checkered & Mexican Eagle which were aftermarket.