Put a 10k resistor in parallel with each of your 350R resistors until you find the one that results in pushing the bridge output toward 0V. Then use a parallel trimpot to adjust that resistor for zero balance.
Put a 10k resistor in parallel with each of your 350R resistors until you find the one that results in pushing the bridge output toward 0V. Then use a parallel trimpot to adjust that resistor for zero balance.