For anyone else in the pickle here is what I've uncovered from the TBC manual:
TBC Serial pinouts:
Colors:
Orange
Yellow
Black
Patterns:
On card: Front of machine to back of machine
Black, Yellow, Orange
On Amiga:
On rear portion (toward back of Amiga) of the serial header
Black (nearest Power supply), Yellow, Orange
Dip switches
# - default - use
SW1 - UP - Reserved
SW2 - UP - Baud rate, UP=31250, Down=9600
SW3 - UP - ID
SW4 - UP - ID
SW5 - UP - ID
SW6 - UP - Hot Switch, UP=video freeze, Down=freeze disable
SW7 - UP - Vertical Blanking Width, UP=first - 21st fields blanked, Down=First 9 fields blanked
SW8 - UP - Remote Enabled, UP=Serial on, Down=Disabled (auto sync) When down SW3 controls NTSC (UP) vs Svideo (Down)
ID table:
TBC 1 - SW3 UP, SW4 UP, SW5 UP
TBC 2 - SW3 DOWN, SW4 DOWN, SW5 DOWN
TBC 3 - SW3 DOWN, SW4 DOWN, SW5 UP
TBC 4 - SW3 DOWN, SW4 UP, SW5 DOWN
TBC 5 - SW3 DOWN, SW4 UP, SW5 UP