as per usual, it's our old cheeky little friends at UMC https://mobile.twitter.com/maplesbian/status/1384933252826292225
thanks to http://datassette.org i found a schematic that might not be the exact Dactar model i have but close enough to follow where the PAL-M-responsible components are that need to be bypassed
and it's just neat to look at vintage electronics schematics
addendum: i tried turning up the volume on the PVM and there was no sound either so i think i'm tapping on the wrong place for sound (though following the trace it should be the right place) so i'll shelf this for now but i'll try to tackle these two issues next time
it's done. it's perfect!
found out the video being dark was just the contrast knob on my PVM being left low for some reason, and the audio output worked once i picked another spot earlier in the circuit to tap from. now everything works great