To me it looks like a huge mechanical linkage throttle body with possibly two butterfly valves. Looks like the intake tubing tapers into a larger size going to the TB, than tapers down in size leaving the TB and into the upper manifold, hard to tell with that low resolution picture though. I could see two butterfly valves being better at equalizing the flow between both rotors, but I am no expert that is for sure. :dunno:

Ah ...I see it now ...the wood paneling in the background. Brilliant!
:p: