Glen, doesn;t the contacts circuit board say "Yamaha" right on it? Isn;t that a DX7 keybed in fact? Korg uses them in most of their non-weighted synths. Or was the DX7 only 5 octaves? It is definitely a DX7 style bed. In any case, Yamaha would be the place to call first. I'll bet my lunch money it is a Yamaha right off the shelf bed. And I ain't eaten yet today. I'd ask if the aftertouch ribons were available as separate parts.
Looking in DX7, I see "sensor" which is probably it. The DX7 bed is originally from the PF10. I don;t know what they used the 76 key bed in. Just thinking, could you use an 88 strip and curl the excess at the end?
I have old notes that say the strip should show about 6k open and about 10 ohms at max pressure.
I have a Triton Pro X 88 in here now needing a key contact strip. That is wide rubber thing, not metal blades. Korg can no longer supply the contact strip, so I wil have to contact Yamaha for it. Yes it is also a Yamaha keybed. In fact thanks for reminding me to call them while they are still open this afternoon.