Thanks for the link, unfortunately that seems to be all about the canals built north of the river. I did find the U.S. Army Corps of Engineers site, which said that the New Cumberland Lock replaced locks 7, 8 and 9, but it didn't tell me exactly where locks 7-9 had been, so I made a guess that they would have been upstream of where the New Cumberland Lock is now.
I hope you enjoyed the story, anyway, even if I couldn't find info to ensure the historical details were right. Thanks again.

PS I like your icon.