News of Finding Repair Parts (1)

I understand Carrier builds Payne and Bryant furnaces. Are the high efficiency furnaces identical in parts?

The HK42FZ013 Control board is shown as a kit with limit switch, door switch, transformer,and wiring harness. Why do I need all these other items with the control board? I understand this kit relocates the board, but if only the board fails, must I order this kit?

I am looking for a temperature limit switch for a JANITROL MODEL# WH-75 serial #87JH2387R shop gas heater