But now he is using a Fet-input TL082 dual opamp that has an extremely low input leakage current of typically 30pA (no bias current) for your un-necessary additional resistor.Have you tried my suggestion of introducing a 180K ohm resistor between the current sense monitor point and the positive input instead of directly connecting the positive input to the current sense montoring point? This may avoid the need for the nulling.
hgmjr
A 741 opamp would need the additional resistor but since its input resistance is so low then its gain will not be accurate.