Sullivan does not list these as the work of George H. but the following entry from The Bankers Magazine and Statistical Register, July 1873 to June 1874, does attribute these to him:
XIV. New Medals - Mr. Edward Cogan, No 408 State St, Brooklyn N.Y. offers for sale three new medals:
1. The Memorial Medal of the Boston Numismatic and
New England Historic-Genealogical Societies etc.....
2. The Johnson Medalet, referred to in the February Number of the Numismatic Journal. Obverse—a bust of the late President; legend, "Andrew Johnson, 17th President of the United States." Reverse—combined arms of the United States and New York City; inscription, "Public Reception and Banquet by the municipal authorities of New York City, August 29, 1866." Size — about that of the half-dollar. Number struck — silver, 5; copper, 50; tin, 75. Price—in silver, $3; copper, $1; tin, 50c. The work is done by Mr. G. H. Lovett.
A Memorial Medal, designed by an alumnus of Haverford College, and executed by the well-known artist, Geo. H. Lovett, of New York. etc......
Sullivan only list copper and white metal varieties so he either did not know of any silver examples or if only 5 were struck there may not have been any still in existence.