Commodus Medallion Converted into an Amulet?

CNG 102, Lot: 1012. Estimate $1000. Sold for $950. This amount does not include the buyer’s fee.

Commodus. AD 177-192. Æ Medallion (43mm, 62.88 g). Rome mint. Struck circa AD 190. IMP COMMODVS AVG PIVS FELIX, laureate, draped, and cuirassed bust right / MA/PERSE/BEΛI in three lines (letters cut incuse and reversed in mirror image). For obverse type, cf. Gnecchi II 104 and Banti 305. VF, green, red, and brown surfaces, some roughness.

From the estate of Thomas Bentley Cederlind. Ex Peus 413 (29 October 2014), lot 363 (hammer €1000); Peus 400 (22 April 2010), lot 447; Numismatica Ars Classica R (17 May 2007), lot 1559.

The reverse of this medallion has been completely smoothed and then re-engraved in antiquity with an inscription, to perhaps serve as either a stamp or an amulet.