Watch List notes:

ITALY, Napoli (kingdom). Carlo I di Spagna (Carlo V, Sacro Romano Impero). 1516-1554. AR Mezzo ducato (33mm, 14.88 g, 6h). Napoli (Naples) mint. Struck 1548-1554. Laureate and cuirassed bust right, slight drapery on far shoulder; (IBR) to left / Crowned double-headed eagle with coat-of-arms on breast. MIR 135; Pannuti-Riccio 15. Good VF.

From the Richard L. Horst Collection. Ex Classical Numismatic Group Electronic Auction 340 (3 December 2014), lot 509.