If it were me, I would stick the 2067 on a freq and set the mode to PL and let it detect the various tones. If a tone of 136.5 with the little lightning bolt comes up for a short period of time (right at the end of a transmission), they're using DCS, as 136.5 is the end of transmission tone for DCS programmed radios. Sit with it for maybe an hour or so, and just glance up every time you hear something. After you're pretty certain you got all the PL tones and you saw short bursts of 136.5, let it sit on DPL mode and have it detect any potential DCS codes going around.
Once you figure out the different tones/codes, program that freq with all the tones/codes you've logged into a (preferably empty) bank and let it scan only that bank. Sit with it again and listen every time something comes up. If you figure out what business uses what tone, program the name into the associated channel for it.
This is just my strategy, I'd leave the 996 as normal but if you want to expedite the process a bit you can let it sit on a different freq. The 996 should just auto detect the tone or code without you having to do anything as well.
