I cannot find any tech info on the given model number, please check it.
There is info on a 5570.

I've replaced the thermal fuse, high and low limit thermostats and heating element. Heated for one load, then shut off breaker, then when breaker was switched back on--no heat again. All parts show continuity.

Need more info.
What was the original problem?
You said "shut off breaker", did you shut it off or did it blow the machine trip the breaker?
When you checked continuity did you get actual resistance (ohm) readings?

Since the breaker shut off I would start by checking the voltage. The heater requires the full 240 volts.

Try flipping the breaker off/on slowly a couple times, sometimes you can loose half the line without actually tripping the breaker.
If this does nothing, check the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
[COLOR="Red"]Be careful as 240 volts is lethal !!! [/COLOR]