The noise floor on my Quant Asylum QA400 audio analyzer is too high to measure the Muffsy MC Head Amp. Fortunately, Quant Asylum themselves have the solution, use a high quality preamp to lower the noise floor: http://www.quantasylum.com/content/Home/tabid/40/Post/205/Extending-the-QA400-Noise-Floor-with-a-Pre-amp
So... Looking at the Muffsy MC Head Amp, I realized that I do indeed have a high quality preamp sitting right in front of me. :)
I grabbed one of the prototype boards, one of my old PSUs, a back panel and an enclosure and started soldering, and there's the measurement preamplifier. It will be modified by using multiturn trimpots for variable gain, but there it is. I am now able to use the Muffsy MC Head Amp to measure the Muffsy MC Head Amp!