Great, thanks.
Looks like there is nothing special except that PLD used for address decoding (mostly known already) and interrupt/status control. No more surprises left, emulation will be done someday...
Unfortunately there is nothing interesting to emulate, only need to read chip datasheets and emulate required parts, use OS built-in codecs to decode sound and video and finally emulate some genlock features..
Painfully boring but it needs to be done!
(and final result most likely will have crappy sound and video sync)