Replacing 75 ohm heating coil with resistors?
NO! You buy a step-down transformer with a 12vac output that also isolates your fan from the AC line. You need to check the motor current rating and buy a transformer rated 150% of the motor current. Should not cost much. Connect the 12 VAC leads to the input of the rectifier bridge. The motor should be getting at least 16 VDC to 18 VDC.

Do not bypass the thermal fuse. It can be physically mounted to the transformer to kill the power if the transformer overheats-but there should be no reason for it to do so.

The thermostat and resistors can be discarded.