I have 8 White-Rogers Type 1F97W-71 thermostats. Three have broken batter contacts (due to corroded batteries). It looks like I could pull the metal contacts out and replace the contract. Soldering not a problem Are the batter contract available? If I have to replace the thermostat, what is the cost of a similar model and the cost of model with out automatic change over (heat/AC) but with the 4 time and 4 temp programmability.