Sorry for the delay, I have been out of the office due to some bad weather.
To answer your question, I want to be able to see any information at all about the client. I have an IP address, but if I could possibly see what type of device it is or get very very lucky and tie it to a person that was in our building. To be honest, it feels like a pipedream but I'm trying.
I've done reports for client session and client usage but they really only show things like top 10 clients and this particular client didn't make it into the top 10.
The client inventory report sounds promising but I can't back date it to a previous date.