1000 to 5000 is my best guess, half of the bridge is 4.99k 1% resistor connected to a 50 ohm 25 turn trim pot, the other half is 350 ohm per leg strain gauge
Would an amplifier with a log response (or other non-linear response that helps compress the range) be useful? I've been tinkering with a bridge to make some measurements and the null would be very deep, in a relative sense. A friend who is in the business suggested a particular log amp. I put the project down until summer is over. It's not something I know much about but his suggestion made perfect sense.