Hi there! I know this is quite a few years after you posted this question but I did want to respond. I do not know of any photos that exist of William. The only photo I have is of his tombstone and I was SO happy to get that! ;o) Hopefully something will come up.
Until then, let me ask: in the 1850 Census, William is listed with his father, at the bottom of the family group (and it notes he attend school within the past year). Interestingly, underneath him (and with a separate "family number" next to her name) is Malvina Adams, age 17 (who did not attend school within the past year) and a young girl, Sarah F Adams, age 4.
Why is this so? Why would she have a separate family number and yet still have the last name 'Adams'? Who is the little girl? I don't have a Sarah listed as a child of William and Malvina... questions questions... ;o)