The first part of this study analyzed the spatial-temporal error distribution of the Lux-type limited lead system. Quantitative new evidence is reported that the 32-lead anterior subset estimates the further 160 leads with an average amplitude error less than 38.5 microV. The spatial error distribution revealed 8 sites where the error is the highest, primarily on the anterior side, independent of the clinical classification. The second part of the study examined inter-lead-system conversion strategies for interpolating the Lux-192 lead maps from the Montreal-63 data. The methodology based on the Laplacian interpolation yielded an average amplitude error of 143.7 microV and an average correlation of 0.87 for pattern fidelity. In this specific case a modified linear interpolation surpassed the Laplacian method. A presented example illustrates that even in cases when the fidelity of the signal information is heavily compromised the diagnostic information may remain less influenced.