This reproducibility bundle accompanies Phase-Locked Local Grain Coarsening in an Endogenous Walker Clock. It contains the Python scripts, source data, generated figures, logs, checksums, and original SIW reference code used to reproduce the local readout audit reported in the paper. The experiment tests whether local integer-convolution grain coarsening can arise from an autonomous self-interacting walker history rather than from a constructed static support geometry. In the tau = 0 flip-clock orbit, one phase of the endogenous 10-step recurrence produces phase-locked local gcd coarsening: m_W grows across repeated clock cycles while the local capacity, occupied overlap-value count, and normalized local readout distribution remain invariant. A tau = 12 control, audited with the same local readout window and kernel, produces no m_W greater than 1 events. The bundle also includes a forced periodic-word diagnostic showing that periodic U-turn words can generate local gcd coarsening under controlled forcing, and an operational verification script comparing the carried-forward audit against the original SIW implementation. Contents Source scripts for the phase-locked grain-coarsening audit Forced periodic-word diagnostic scripts and outputs Autonomous tau = 0 and tau = 12 clock-audit outputs Original SIW reference code used for verification Generated CSV data Generated figures Logs, manifest, requirements file, and SHA256 checksums