Well, well—and welcome aboard SubRonLA, liftmys10!
There's a ready-made Merriman/Caswell tube out there available for this boat, of course. And I happen to know that Bob Martin in Florida has a Big Dave RCABS system—currently in kit form—designed to fit the Revell Gato which you could acquire from him either as a kit or as a buildup, should you want to pay him to put it all together. Personally, Big Dave himself is constructing a custom RCABS system for my own Gato project (Harder) whenever I get a chance to finally build it...
Sure writing is easy: just sit staring at a blank page until the drops of blood start forming on your forehead.