The understanding of the structural and functional complexity of multi-contacts discrete interfaces is an important issue in many industrial applications. To suggest new research tracks, we studied new and used catenary/carbon collection strip contacts at both the real operating scale and the reduced laboratory scale (reduced force and current ranges). With a view to compare the effects observed at both scales, we collected both surface topography data, microstructural properties of these materials completed with I-V characteristics and voltage creep curves of new and used contact interfaces catenary/carbon stripes obtained in a wide range of temperatures. The discussion of the results highlights the importance of the knowledge of the structure of the contact interface. We show how to use surface topography data to reach the structure of the contact interface through a new numerical method. We use a numerical code allowing the reconstruction of the spots distribution through the simulated compression of the actual surface charts of the contacting solids. The features of the numerically reconstructed interfaces are discussed and compared to our experimental data to establish the relevance of the method.