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The thumb has also been featured in Christian History and Biography (Winter 2004) and The Chronicle of Higher Education (October 28, 2005).
That's the only actual body part, although the Methodist Library does have Wesley's death mask (making death masks was actually a fairly common 18th-century way of memorializing the dead). Also, the archives of the Greater New Jersey Annual Conference, which are in the Methodist Library building, have the shoes of a woman who was struck by lightning and survived.
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Thomas A. Tweed, "John Wesley Slept Here: American Shrines and American Methodists,"
Numen, Vol. 47, No. 1 (2000), pp. 41-68.