From the Heritage Galleries Auction Listings:
1910 1C Lincoln Cent Obverse Uniface Test Strike. AU58 PCGS. Struck on slightly larger than normal planchet with a very deep and bold strike. Traces of mint red in the protected areas and no disfiguring spots are present. This coin was probably made to test the die and striking pressure needed to bring up the device detail fully. An unusual item which is seldom offered and undoubtedly rare.
1999-D 10C Roosevelt Dime--Broadstruck on a Cent Planchet--MS64 Brown PCGS. A dramatic error that accentuates the fact that the planchet was incorrect by the broadstruck features. The devices are generally sharp although some of the peripheral lettering displays the distortions caused by the expansion of the planchet during the strike. Traces of zinc alloy are seen in a few places on the obverse and reverse.
1999 1C Lincoln Cent Obverse Die Muled With a Roosevelt Dime Reverse on a Lincoln Cent Planchet MS66 Red PCGS. This incredible error somehow escaped the scrutiny of Mint employees. We are uncertain how a Lincoln cent obverse die was paired with a Roosevelt dime reverse, but this coin proves that it happened. No others are known to exist: it is believed that the present muling of a cent obverse with a dime reverse is unique. Cross-denomination errors are all but unheard-of from the U.S. mints. The only other examples that come to mind are the Sacagawea dollar/Washington quarter mules, of which about a dozen are known. Incredibly, this type of error occurred only recently, during the entire history of U.S. coinage that spans more than 200 years.
The obverse is sharply struck on the figure of Lincoln and the date, although the opposing dime die, being slightly smaller than the cent planchet, caused minor peripheral weakness on the obverse. In other words, nothing was behind the periphery of the cent die to force the expanding metal into the recesses. Naturally, the slightly smaller reverse dime die caused that side to be boldly struck. Shortly after this phenomenon dropped from the (mismatched) dies, it was discovered in a jewelry store in Michigan before entering circulation. It has since been carefully handled, and has developed no spots or other distractions. The coin remains a solid Premium Gem MS66, with full mint Red.
For the error specialist, this would be the centerpiece of an advanced collection. All error collectors will long remember the present coin and hope that someday it will again be publicly offered. This piece was widely publicized in Coin World and Numismatic News soon after its discovery. Since then, it has passed to two or three owners. This prize represents a unique opportunity. It is undoubtedly one of the most important highlights of this or any numismatic auction.
1964-D 10C Roosevelt Dime--Struck on a United States One Cent Alloy Planchet. MS64 PCGS. An important error struck during the final year that the silver dime planchets were used for circulation. Demand for coinage was tremendous in 1964, and the mints struggled to keep up with the endless stream of orders as the roll boom was in full swing. This coin was probably created when a strip of copper (for cent planchets) was mistakenly run through the planchet cutting machine when it was set for dime planchets. Thus copper dime sized planchets were made and this particular one made it through the coining process and escaped into numismatic hands. It would seem logical that this type of error would be far scarcer than a dime struck on a cent planchet. A thin die crack extends from the rim through IN toward Roosevelt’s chin.