John
Thanks for posting the pic, it looks good. After looking at the pic a while, I went and got my f-70 out and have an idea you may want to consider if you redo yours.
What do you think about placing a long strip of the grip material up and down the handle left and right sides going underneath the rod assembly as your first strip. Then wrap it as you would otherwise. Doing it this way may conceal the foam grip on the bottom area and add some meat to increase the grip size some more. I suppose for more meat you could also use additional strips on the front and back side of the handle too and then wrap it.
At this point, I am digging more than swinging the F70 so at the moment I have no immediate plans to do anything, however, I do like the idea !
Tony