I'm curious as to how the output transformers in your ST-120 kit compare to the outputs of the stock ST-70 (core materials, laminations, bandwidth, winding ratio, UL tap %, etc...).
I'm also wondering if you've ever experimented with mono-blocking them Mk.III-style, and if so, could a Mk.III-compatible driver board be used? What would the requirements be for a pair of power transformers in this configuration? Could the Mk.III chassis be used?
Sorry, but I've been wondering about this for a while now....