Quinn Jacobson, the outstanding wet plate photographer and teacher (and all-around great guy) sent me this:
"There are several places he can get chemistry. The easiest and best price would be a place in Darmstadt - Wolfang Moersch Chemicals - http://www.moersch-photochemie.de/. He also has other contacts in the area. Have him contact Wolfgang.
I hope that helps."
And thank you, Quinn, for your help!
(see Quinn's beautiful art here: http://studioq.com/)