"Capps Lincoln-Koke Beidler" picture, p. 18;
Mount Pulaski, Illinois 1836-1986 150 Years of Memories
; CW 1986, Mount Pulaski Community Pride; Charles W. Fricke, Editor; Kes-Print, Inc.; 8419 W. 72 Terrace; Shawnee Mission, Kansas City.  The above reference including the "...Ambrotypefrom life..." quote is to be found in the caption to this picture in that 1986 anniversary hard-back 720 pp. book.

Photo of bust of Lincoln taken from bust
that is on display in MPTHS Museum.
This is a copy of Volk's original:

Leonard Volk (1828-1895), after studying sculpture in Rome,
he opened a studio in Chicago in 1857. Volk met Lincoln during
the 1858 debates and, in early 1860, persuaded him to sit for a
 life mask on March 31. From this mask, Volk made several
different versions of busts. In May of that year, he produced
Lincoln's hands. Both the mask and the hands provided models
for many other Lincoln statues by many other sculptors. Volk
also produced life-size statues in Springfield, IL and Rochester,
NY.