This period is marked by the introduction of the ersatz coinage metal euphemistically called "nickel clad" and more picturesquely known as "sandwich metal," layers of cupro-nickel (as in regular 5Â¢) bonded to a copper core, a combination chosen by the Battelle Institute to avoid forcing the Mafia-controlled vending machine industry to suffer any inconvenience. My objection to this metal has been in print more than once: it eases the counterfeiter's task, and makes his product harder to detect, discarding anticounterfeiting tests in use for thousands of years. The coins are underweight, ring poorly and briefly, have bad color and greasy feel, and relief detail - even on proofs - is inferior to that on earlier years. The quarter from 1965 on is from redesigned obv. and rev. hubs copying 1935 (though the 1968S and later proof quarters have a better reverse).
Nor can this section be complete without mention of the ersatz proofs called, again euphemistically, "Special Mint Sets," made 1965-67 at the reactivated San Francisco Mint, and sold in quantity at about double the price of former proof sets. Striking quality is inferior to proofs and to pre-1965 uncirculated pieces; nicks and scratches are the rule.
But the following proofs are the real thing.
Five Cents.  Initials FS added to obverse. Struck to honor the late Felix Schlag, one presented to him at a ceremony. One wonders if his widow has already been harassed by ambulance-chasers in search of the coin.
Set. [3,041,509] S Mintmark on obv. in all denominations henceforth. A few lack the S on the dime; mintage unknown but very small, survivors extremely rare and unpriced in standard references. No late auction records. The majority of sets have "Type III" quarters: leaf does not extend above point of topmost arrow. "A substantial minority", issued Nov.-Dec. 1968, have "Type II" quarters (as in all following dates of proofs): leaf extends well above arrow points; leaf joins A; M (of UNUM) directly below 1B.
Set. [2,934,631] S Mint. Nothing remarkable except the year itself, notable for the first moon landing and the Woodstock Festival. Head on cent slightly smaller.
Set. [2,632,810] S Mint. Several variations. Type I: Small date cent (tops of digits even, base of 7 about in line with that of 0). Much scarcer than following.
Type II: Large date cent (tops of digits uneven, top of 7 below 9-0, base below 0).
Some 2,200 were made with dime lacking the S (which type cent?).
A quarter is known in silver, overstruck on a 1900 quarter (clear date)! Winthrop: 1020, $3,000, later NERCG "Cambridge" Sale:1440 (12/76).
Set. [3,224,138] S Mint. The 5Â¢ is from a remodeled (slightly modified) hub, the design a little strengthened. Half dollars, formerly 80% silver clad to a 21% silver core, are from now on made of the same nickel/copper sandwich metal as dimes and quarters. The Ike dollars (below) were not included in these sets, though many were later added by buyers of the sets.
Some 1,655 sets lack mintmark on the 5Â¢. Very scarce and in great demand.
Dollar. Eisenhower design, silver-clad. [4,265,234] So-called "high relief" dies. Sold separately from sets. Average die life 3,500 impressions.
Set. [3,267,667] S Mint. The 5Â¢ was again slightly remodeled. No dollars included.
Dollar. Silver-clad. [1,811,631] "High relief" dies as above. Sold separately.
Set. [2,769,624] S Mint. The cent was slightly remodeled, Frank Gasparro's initials FG enlarged. Quarter reverse details are sharpened. Sets include nickel-clad Ike dollars for the first time. These have "Type C" reverse, no incuse outline behind lower r. crater; three distinct Caribbean islands left of Florida.
Dollar. Silver-clad. [1,005,617] "Modified high relief" type. Sold separately from the sets.
Six-piece Set. [4,149,730] S Mint. Same composition as 1975, nickel-clad Bicentennial dollar included. Dollars come in both Var. I (above) and Var. II, latter with sharper design, more delicate rev. lettering, curved tail to R of DOLLAR, some other letters altered in shape.
Three-piece Set. [1,045,412] Quarter, half and Var. II dollar only, all of Bicentennial designs; silver-clad.
Set. (Still in production) S Mint. Nickel-clad quarter, half dollar and dollar; designs revert to those of 1974. As this is written there is talk of discontinuing the dollar; orders are nevertheless being accepted from April 1, 1977 for the above described sets, not over five per person, at $9 apiece compared to the former $7. Although the $2 increase would seem to have dampened collectors' enthusiasm still the rumors are that well over 2 million have been ordered.