When I counter balanced mine... I cut the vertical fin in half and used the top half as the counter balance. I'm getting ready to build another SE this winter and plan on several other mods too. (my other SE had an unfortunate meeting with gravity but it lasted about 3 seasons so I'm do for a new one anyway)
I did pull-pull on the rudder, used a dubro main gear, added a tank hatch and plan on all of these on SE #2.