Correspondence with Leroy Van Allen, including drawings and extensive published clips. Most of this material is in-copyright, please contact NNPCurator@wustl.edu for access. Clips included are:

The Errorgram, Vol. 14, nos. 29-45 (5/18/1978 to 9/7/1978), containing articles by Leroy Van Allen on coining technology.

Leroy Van Allen, “Malfunctioning feed fingers cause of errors” (Coin World, 10/8/1986).

R. W. Julian, “Steam technology delayed 1836 half dollars” (Numismatic News, 3/9/1999).

Victoria Stone, “Close call : Close collars eliminated some edge devices…” (Coin World, 3/8/1999).

Michael Hodder, “Is it a Proof? Line between Proof, prooflikes blurry before 1828 close collar use” (Coin World, 9/28/1992).

Breen’s Encyclopedia, pp. 305, 698. 703, 705.