I think measuring the distance in millimeters will get you to a better idea which part is causing this.
I found a manual that says for toner cartridge:
Drum is 62.9mm, Developer roller 35.1mm, Charging roller 26.7mm, Supply roller 47mm
Fuser parts are:
Pressure roller 75.4mm or Fuser roller 77.5mm
You should be able to measure from 1 line to the next to see what’s closest. Sometimes they are hard figure out when they are similar sizes but these are different enough it should get you an idea where to start.