[polyglot]

Glad to be of service!

There's something wonky with your scan though as the highlights are clipped to pink (it's clearly a digital artefact, not chemical). My guess is you adjusted the colour balance after setting the black & white points, which means clipping the image and then modifying the colours so the net result is the white-point is no longer white. You need to get the colours right during the inversion before clipping the dynamic range to an 8-bit file.