The preview shows what the camera's look table does to the picture. It is an approximation of Lightroom, not Adobe's own maths.
ML/data/FOSFILMS.BIN and, for each look you made, ML/DARKROOM/PLOOKnn.LUT.ML folder from the ZIP onto the card, over the files with the same names, then start the camera. Your new looks are at the end of the Presets shelf.Rolls you did not touch are written exactly as they were. New looks add a roll to the end of the Presets shelf, with its own look table. Only a roll's names and its label colours and wording can be edited here. The eight rolls built into the firmware are painted by its code and are not in this file. The preview is an approximation of the camera's renderer.