This is how I did it...... I made the Clem into the Eisenhower by
changing the shape file in the CLEM.NT file from the clem.sh to the
nimz.sh and by copying and renaming the NIMZT.SH to CLEMT.SH thus
replacing the clem tower... Thus I have Two Nimits class carriers...

Addition editing will be required of the skin files as the towers now
overlap the deck edge elevators but this is just a texture fix to
solve..

Next to get another Kittyhawk class carrier I simply replace the
NIMZ.SH file in the NIMZ.NT file with a new Conn.SH fle(renamed and
hexed copy of the KITT shape for Constellation)and replaced the
KITTT.SH file in the ~KITTT.NT file with CONNT.SH(hexed copy with new
skin of the KITTT.SH file) thus I have two new Kittyhawk class
carriers with towers and the Eisenhower...

Now to get the Clem back as a usable carrier I simply added another
carrier and used the CLEM shape .. The clem shape and tower are hard
linked thus you dont lose the tower when you make a new one..

Also to make an additional Clem shaped carrier simply use the XCLEM
shape(You will have to copy the CLEM_A.SH shape and rename it
XCLEM_A.SH if my memeory serves me) in another NT file and you have
two Clem shaped carriers.......

So as you can see there is really no mysterious way to make new gains
in FA, you just have to do some unorthodox thinging is all.....

Just let you imagination wander and you usually end up finding
solutions...