Looks to be signed by Italian artist Constantino Affer known for his Papal medals, Olympic medals and Apollo medals, most around 50mm or larger, almost all are done in Bronze and silver plated. I can't help you with value, but I see other similar ones offered in the range of $15-50 range.
Found the Pope Johannes XXIII on
ebay:
http://www.ebay.com/itm/Vintage-Pop...151215665725
"Buy the Book Before You Buy the Coin" - Aaron R. Feldman - "And read it" - Me 2013!
ANA Life Member #3288 in good standing since 1981, ANS, Early American Coppers Member (EAC), Colonial Coin Collectors Club member (C4), Conder Token Collector Club member (CTCC), Civil War Token Society (CWTS) member, Liberty Seated Collectors Club (LSCC) & Numismatic Bibliomania Society member (NBS), USMex, Member in good standing, 2˘ variety collector.
See my want page:
http://goccf.com/t/140440