As a suggestion take the whole setup to some one who can look it over and give you the advice you need.
A two channel setup like you discribe is most likley very old and illegal to use as well as having very old batterys....replacement cost on the batterys will make it more practicle to buy a complete entry level 4 channel, servos and new batterys.....something to think about.
You need personel help at this point, we can discuss it here but in person is beter.