There aren't schematics around for the Mic Pre, but you can find one of the Line Amp stages for TG series, it uses BC109 transistors though. You would need to do some things to match impedance for a mic input and find a way to adjust gain. There is also a document out there that describes in great detail how the EMI TG series consoles work, but the schematics were removed from them. I tried to design a filter using the descriptions in that document but it uses a weird design and the descriptions were very vague. It's some type of LCR filter implemented between 2 transistors using both positive and negative feedback, and use an attenuator to boost or cut the gain.
If any one finds any other EMI schematics please let me know. By the way, I plan to be molding some knobs for my TG Limiter soon, in red, if any one is interested.