Can anybody identify the cachet maker for this C12 FDC?

It is not in Planty. The envelop was made by Roessler, but that doesn't necessarily mean the cachet is his. But does anybody know one way or the other? FWIW, the exact same cover is currently listed on
ebay, right down to the addressee:
http://www.ebay.com/itm/like/201208638558?lpid=82Which I guess raises the question, is the name "A. F. Witmer" significant in any way? (My google-fu comes back clueless.)
TIA.
Basil