kciggster

I have a Gas Water Heater that states it was manufactured by State Stove and Manufacturing Co in Henderson, NV. The Model# is C4 40 TMH. The serial# is K75100124. Does this mean the water heater was manufactured in October of 1975? The reason I ask is that my gas bills are high in the summer months and when we take showers the hot water only lasts about 10 minutes. I spoke to the gas company and they said the problem is likely the water heater. The only other gas appliances we have are the furnace (which isn't used in the summer) and a gas stove (which isn't used that much in the summer because I BBQ). Should the water heater be replaced? Thank You