Want to know the relative importance of fielding and RBIs? All-time glove man Brooks Robinson won 1964's AL MVP with 18 of 20 1st-place votes. "Dr. Strangeglove" Stuart posted similar offensive numbers--and finished 28th.
Glove worries aside, Dick did make the All-Star game in 1961 with a SABRmatrician-friendly season. Despite leading the AL in only one category (strikeouts!), he hit for 139 OPS+ and 3.2 offensive WAR, both significantly better than what 1964's apparently similar "core" stats (hits, homers, and RBIs) produced.
1965 marked Canadian candy maker O-Pee-Chee's first Topps-licensed baseball set and matches the American design word-for-word, other than "PRINTED IN CANADA" on its back. (Compare this to my 1965 Topps #5 profile for confirmation.) OPC stopped at #283, less than half of Topps 598-card checklist. It's rare and includes plenty of stars, making a full set tough to assemble.
Value: This #5 cost $15 on eBay, probably because of the blue ink. OPC HOF cards usually cost more.
Fakes / reprints: Haven't seen O-Pee-Chee "reprints" in the market, but it's possible someone faked it for the Mantle.