I am interested in all (occidental) SENG family history, and am currently working on the "Louisville" Sengs.I've made several contacts and received much info, but not the datum you're looking for. Maybe I can put you in touch with the folks who corresponded with me, but first a question:Could "your" Nicholas Seng be the brother to Kilian Seng who was born in Winnweiler(Rheinbaiern) in 1808 and emigrated to (eventually) the Louisville area?In the listing I have received, Kilian's clan is well documented, but there is only a note that "Kilian had two brothers, Nicholas & Henry," nothing else is provided. Kilian also had a son, Nicholas (b.1848 in KY or So.IND.) who married a Mary Miller (Mueller?) in the 1850's & fathered 10 children with her--his second wife.
If you're sure you N. was born in Baden and not in Rheinbaiern (Pfalz), there is a remote possibility that another family now mostly in the Evansville, IN area might be related.Even if he emigrated from Baden, there is chance that he is a "Louisville Seng."