Installing 13 gallon fiberglass fuel tanks

[KNickman]

I bought two 13 gallon tanks from a member for my Kitfox model 2. I believe he used the plans for a model 3 which have the tanks riveted onto the spars, so he riveted his tanks to the spars.
I was given the Kitfox IV plans for installation for wing tanks by another member. These plans specify using RTV to glue in the tanks - no rivets.
Is it sufficient to glue in the tanks? What size rivets should be used if any?

To further complicate the installation, the right tank has a 1" twist rather than the 1.75" twist used in the Model 2 wings. I shimmed that tank on the back spar so the front of the tank is flat on the front spar. This makes the left rear of the tank slightly above the rib #1 capstrip. I guess this will have to be faired in with the fuselage.
Any suggestions?

[KNickman]

Jim Chuk convinced me that the RTV was sufficient. I also saw the thread where someone had to work hard to remove their fuel tanks that were stuck in with RTV.