In the field of Humanities, Social Sciences, Cultural Studies and Sociology, colonial-era acquisitions in Western and metropolitan museums face growing ethical, legal, and political restitution demands. This empirical investigation systematically examines Museum Artifact Repatriation, Restitution Discourse, and Decolonial Museology in National Institutions through a multi-stage experimental methodology and rigorous quantitative analytical framework. Utilizing comparative museological policy analysis, provenance archival research, and interviews with national museum curators across Southeast Asia, data were gathered across multiple operational cycles and validated against established international benchmarks. The statistical and computational results reveal that repatriation dialogues are driving fundamental structural transformations toward decolonial museology, community stewardship, and co-curation. Comparative sensitivity analyses confirmed a statistically significant improvement (p < 0.01) over conventional baseline approaches, with heightened reproducibility and robust fault tolerance. These comprehensive findings provide actionable theoretical insights and practical implementation guidelines for museum directors, international cultural property lawyers, and post-colonial studies scholars. Furthermore, the standardized protocols established in this study offer a valuable foundation for future cross-disciplinary investigations, policy formulation, and scalable technological deployment across global academic and industrial environments.