Your in luck I built one of the first kits produced by R/C City when theywere still in Northern California. All I got at that time was a moldedglass fuselage and foam wing cores.I had to make my own drawings for the float attachment and draw up bulkheads for the fuselage and floats.I flew this model at the Lake Havasu Schneider Cup races in1993.
In addition a friend of mine built one also and we came in First and second. I still have a video tape I made showing how I was building the model. I use to send it back and forth as we progressed.In addition,I sold the drawings of the S-4 to the new owner(they went broke) because he had an order from Japan for ten kits and needed drawings.!!!!!!
The model flew very well and I sold it to a gentleman back east.
If I can help please advise. Best of luck, Don Panek