Doesn't there also exist an adapter that sits underneath Denise? Might be easier to fabricate your own one of those, as opposed to fab'ing a PCB and pin headers to fit in the video slot.
Or I suppose an Indivision ECS would also work, provided you can find the proper pinouts and the signal is compatible. Personally I've had good success running an Indi ECS through a GVP Spectrum, but could never get it to work right going through the switcher on a Picasso II. But YMMV. Good luck!
