One of the caligae type shoe found during excavations in the city of Mainz, Germany. The original is on display in the splendid DLM Deutsches Ledermuseum Offenbach.
An interesting detail that is often overlooked with the Mainz caligae is their additional decorative strips at the front (beyond the quite common ones at the back). Caliga no. 9 had them as well although only the first few millimeters remain. I copied the surviving finial of caliga no. 2. The nailing pattern comes from another find from Mainz, caliga no. 1. With these I especially like their additional decorative strips on the lower of the pair of tabs above the ankle. A nice twist to what you normally see on reproduced caligae.