Have you contacted Richard Stubbs at MFJ Customer Service? He's found and scanned older paper manuals for folks before.
Does anyone know, since I have yet to find a schematic on the Rev 1, 1994 configuration, if this voice keyer works differently then the one that is Rev 2, 1995? The Rev 1 I have seems to require to be powered in order to pass your audio form mic to radio (thru the 432) regardless if you want to use the 432 or not, and even with PTT, audio from the mic to the radio will not pass to the radio unless the unit is powered "On". The Rev 2 isn't this way and I noted there are many component changes when comparing the two, but since I cannot locate a schematic on the Rev 1, no telling what exactly is differing.
My thoughts are the Rev 1 is just as it is and the Rev 2 "corrected" this, but MFJ has yet to confirm that..
Anyone know anything on the Rev 1 version?