Matched transistors in Threshold SA/_e amplifiers?

This question is for Nelson:

I have a few of the Threshold SA/_e amplifiers (SA/12e and SA/4e), and was wondering if the TO-3 output devices has been matched in any way when these amplifiers were produced? If yes, could you tell me what the matching process and criteria were?

I see no markings on the output devices, so that made me curious.

Thanks,

Michael