The IPC shows the Headset jack to be at the extreme left/right of the stationary panel (see item 2). My (‘53 model) headset jacks on the left are both (mic and ph) there placed adjacent/vertically…and on the right they are installed in a blank inst hole (not what I would have done but what the previous owner did and I’ve been too lazy to change it.)
The sidewall upholstery can make it a “tight” installation…but it’s do-able, and if you leave your headsets in the airplane shouldn’t pose a problem.