Your right the the Tracker 2000 is a good piece of test gear.
The grey Tracker 2000 has 4 pins as does the DSI700.
Should be no problem to identify signals on the 4 pins.
I just had a look at my grey Tracker 2000 and found the signals on the pins from the pin nearest the outer edge of the case go as follows.
Pin 1 = +15 Volts, Pin 2 = -15 volts, pin 3 =ground, & Pin 4 = clock at 5 volts TTL level (Pin nearest the mains in).
Looks like the DSI 700 has the same pinout but might be wise to confirm pin 3 is also the ground pin on the DSI 700, but looks like the cable is a straight pin1 to pin 1, pin 2 to pin 2 etc.
The Tracker 2000 "com" is linked to ground but not the DSI 700 until it is connected at the front to the Tracker 2000.
If your brown Tracker 2000 has a 3 pin connector, I wonder which signal is not used on this version.
Hope this helps.