International measurement comparisons are essential to demonstrate equivalence of national calibration and measurement capabilities (CMCs) under the CIPM MRA. Linking enables regional or bilateral comparisons to be related to CIPM key comparisons through the determination of a linking invariant. This work presents the methodology applied to link the bilateral SIM.L-K1:2007.1 comparison to the CCL-K1:2011 key comparison for gauge block calibration by optical interferometry. The uncertainty estimation includes correlation effects, and the transferred Degrees of Equivalence are assessed using normalized errors, reduced chi-squared statistics and Birge ratios, confirming statistical consistency and robustness of the linking procedure.