Sansui AU 6600 Amplifier restoration Power cement resistor tolerance
The datasheet for that resistor says that it has a 10% tolerance.  That's the k after the value (0.47 ohm k.)

So, it's allowed to be between 0.423 and  0.517 ohms.

That you measured 0.71 ohms doesn't mean that the resistor is bad, though.

Short your multimeter leads, and take note of the resistance.  Subtract that from the values you measure for your resistors.

The leads of the multimeter have resistance, and there's a little resistance at the contact points.  Normally, you don't care.  What's 0.3 Ohms when you're measuring 100k ohms?  The values you are working with, though, are so small that you need to account for things you can normally ignore.

Some multimeters have a zero function for this kind of thing.  Short the leads, press the zero button, and the following readings have the lead resistance subtracted.

Your UT61E has this function.  Short the leads, press "rel" and it will subtract the lead resistance for you.