This archive is the reproducibility package for the manuscript "Separating broad-scale and local 3D contamination in magnetotelluric data: A dual-scorer framework for assessing 2D inversion reliability". The package contains the clean synthetic sample tables, derived field-validation tables, Borborema and Los Humeros analysis tables, public residual-validation outputs, repeat-transfer-function instability outputs, plotting scripts, analysis scripts, final manuscript figures, LaTeX source files, bibliography, and the compiled manuscript PDF. Large third-party public archives are not redistributed wholesale in this package. They should be retrieved from their original repositories: SA2022 model and response files (Moorkamp et al., 2022, DOI 10.5281/zenodo.5870585), SAMTEX model-data package (Singh and Dehiya, 2024, DOI 10.5281/zenodo.12581274), SAMTEX transfer functions (Jones et al., 2008, DOI 10.17611/DP/EMTF/SAMTEX), and The Geysers repeat MT data (Peacock et al., 2025, DOI 10.5066/P14BJG2A). Start with README.md, REPRODUCE.md, DATA_DESCRIPTION.md, and MANIFEST.csv. This package contains author-generated scripts, derived analysis tables, final figures, manuscript source files, and reproducibility metadata. Large third-party public archives and external modelling software are not redistributed wholesale. They should be retrieved from their original repositories or software providers. Third-party data products and layers retain the licenses and access conditions stated by their original repositories; derived tables included here are provided to reproduce the analyses reported in the manuscript.