38mm (1.5in) Recessed Basing for Miniature Figures

I was looking for recessed basing for my newly minted and acquired 10mm WW2 Pendraken miniatures and came across OntologicalShock's beautifully crafted Figure Squad Basing https://www.thingiverse.com/thing:2071698, which I modded by adding a flat round disk converted from a flattend Rostock Calibration Cylinder https://www.thingiverse.com/thing:139113. These are sized to 38mm (1.5in) and 4mm tall with a 2mm recess, which apparently is the standard for metal cast figures at many scales. The built