I found out a bit about this company. D.L. Schnabel & Sons was in the business of dried fruit and oak bark (Lohrinde). Apparently the tannin from oak bark was used for treating hide to make leather (hence "tanning").
I found some references to the company in the records of the Royal Trade and Exchange Courthouse in Budapest from 1898:
https://books.google.com/books?id=s7MYAAAAYAAJ&pg=RA1-PA91&...
David was 70 at the time, and his eldest son Edmund was 45. David, Edmund, and Karl were co-owners. Perhaps they traveled to Budapest for the case. Google Translate is not perfect with 19th century Hungarian, but the records seem to reference a suit brought by the company against the Austo-Hungarian State Railroad Company. The company was demanding compensation for damaged goods – apparently sparks from the locomotive had started a fire on the train. The case was rejected on the grounds that the goods were transported in an “open car” under a canvas cover, and apparently the law or contract said the railway was not responsible for damage to goods in open cars. The incident seems to have occurred in a town called Altensteig in the (former) Kingdom of Wurtemburg in southern Germany, so D.L. Schnabel Sohne was likely not just a small local business.
I also found some references to the company in Austrian newspapers from the period:
http://anno.onb.ac.at/cgi-content/anno?aid=nfp&datum=18900803&a...
http://anno.onb.ac.at/cgi-content/anno?aid=wrz&datum=18841210&a...
The 1898 case was not the first time D.L. Schnabel & Sons had sued the Railroad. In 1890, the Vienna daily Neue Freie Presse published an article “on an action [suit] brought by Schnabel & Söhne against the Oesterreichisch-Ungarische Staatseisenbahn-Gesell-schaft. A consignment of Bosnian plums is delayed and in a defective state of rot in Ungarisch-Brod as a result of a confusion about the addressee.” The article goes on to describe the complexities of the case – were the sacks of plums really mislabeled, and who exactly is to blame?
Anyway, I thought this would be interesting!