Hi Greg,
If ACE is just forwarding the client request the you should see the client port and IP at the backend. If ACE is doing NAT then you can try and filter on the basis of time stamps or information in HTTP header like specific client cookie but mostly when you have different front end and back end streams then time stamps are your best option. Normally during TS taking simultaneous output of "show conn" also helps in corelating front end and backend connection. You can take connection ID and see the corresponding backend stream and vice versa
show np x me-stats "-c -vvv"--->where x is NP 1 or 2 or 3 or 4 depending upon the specific connection output in show conn.
Regards,
Kanwal