Due to the chess set that I found, the Bishop did not have a notch on its head but instead had a crown of sorts. This said, this proved to be a little bit more of a challenge then simply cutting a notch into the model. The way I solved it is created a duplicate oval shaped sphere over the head, created a wedge to cut my object from a cone, and modified the sphere so that the final cut would look right. I also modified the Bishop head so that it would be smaller and show the detail that I added! I am definately happy with the result!
My final step after doing the subtractive modifier to the crown will be to do the additive modifier with the main Bishop head
Thanks for looking!