Testing of defaced FETs

Does anyone here want to help in trying to unmask the defaced FETs that you find in some amplifiers? The following is what you'd need for basic testing. Having this work distributed to a large number of techs could defray costs and tests of the same FETs by different techs could help confirm values.

A 12v power supply

A 2 ohm (other values would work but a standard 2 ohm would simplify) dummy load or current limiting resistor (25w or larger)

A way to accurately measure current (any multimeter capable of measuring 10 amps is good enough)

A standard multimeter to measure DCV.

Some form of heatsink to clamp the FET to during testing