ARGENTINA. 40 Centavos Essai, 1879. PCGS SP-64 Secure Holder.cf.KM-E4a (not listed in brass); cf.CJ-29.5 (not listed in brass). Struck in brass. Medal axis. Crisply struck with great luster and mild yet appealing tone. <strong>RARE</strong>.PCGS SP-64 Secure Holder.