I'm not super versed in all the different flavors of the Colecovision and revisions it went through but this one I cracked open recently has a "Coleco Ind. Calibration Seal" on it dated from 5/3/1988 with some serious work done to it. There is heavy modification incuding this resistor ladder on one side and diode ladder on the other side of the controller ICs. Anyone come across this before and if so what is the purpose of this modification? Is this something Coleco did or is this unrelated to the calibration it's claiming to have had done to it?