I found some time this afternoon.
Unzip the attached file, and load it in to your radio with PSREdit500. (Don't forget to save your original config because I don't have it in this file, of course!)
155.97 is listed as the first frequency in the TSYS, so it should jump right in to the system immediately if that is the control channel. All the known CCs in the P25 system are in there, so odds are good you'll get it to work (I hope!). You'll know if you start hearing voice and see a talkgroup in the 500 or 600 range show up on the screen. (If you do, let us know, so it can be submitted to the database.)
When you have a moment, hold on object 1851 (hit MAN, type '1851' and hit the ENT button). From there, press F3 for "Analyze". Use the cursor up and down keys to slowly go through all the frequencies (there's about 25 I think). If any of them come up with the control channel sound, look on the bottom of the screen for the following two lines (the screen will be alternating between the two lines):
Sy:--- R--- S---
00% N03C W:-----
Hopefully those dashes will be replaced with meaningful info, and the '00%' will be closer to '99%' (that's the decode rate). I'm expecting N to be 03C, but it really could be anything - you did see 03C at least once, though.
When you see those, please note down the frequency and exactly what details show up. That will allow us to create a site (or more than one site, if you get hits on more than one freq) in the RadioReference database for your location.