Depending on how old the 7160 is it would have either a TP307 or a TP807 RCU. The TP013 RCU shipped with SD Toppys (5000 masterpiece and 5000 black panther). The default mode for the TP013 is Mode 1, the TP307/TP807 only supports mode 1. If you indeed have a TP013 I am surprised that the 7160 works without the volkey patch TAP. You can change the mode of the TP013 by simultaneously pressing the power button, and either the 1, 2, 3 or 4 numeric key.
You do not need to do anything with the 7170, but with the 7160 you would need to have the RemoteSwitch TAP running, and activate either mode 2, 3 or 4, and change the RCU Type to 5000 Masterpiece. Make sure than mode 1 is inactive.
The Harmony RCUs are relatively easy to set up. You would set the 7160, and then set up an RCU that will work with the 7170 as the second. The TP501 (TRF-2400/2460/2470) does not work with the 7160 (with the December 2013 firmware) as the function keys are not recognised; you would have the same problem with the mode 6 RCUs (TP602, TP850 and TP857). I will test my 7160 tomorrow, I just updated to the Feb 2015 firmware and it may now work with the TP501 or the mode 6 RCUs.
In future I suggest asking questions on the Topfield Australia Forum as you will be likely to get a more timely response.
Ian