Both the F28 series 1000 and series 4000 as operated by USAir in 1992 were configured with just four seats in first class in a 2-2 layout.
Curiously, I encountered such a configuration on another occasion.
Aer Lingus bought a fleet of 737-500s in the 1990s. As standard in Europe, they were fitted with convertible seats at the front, adjusted with a winding handle (or strong arms) between 3+3 and wider 2+2 with a small area in the middle where the centre seat was. The seat covers were green (of course), with quotations from Irish writers (Oscar Wilde; George Bernard Shaw, etc) written all across in an old script handwriting. It used to be an entertainment during the flight to make out what was written. I was in an EI -500 from Cork to Paris, during an extended business trip around Europe one time.
They were eventually replaced by A320s, and sold to Pulkovo Airlines (nowadays Rossiya) of St Petersburg, Russia, still with Irish registrations. For some years they ran to London, replacing the Tupolev Tu154 (shame). Economy class only, they kept those same green seats with the Irish literary quotes. Goodness knows what Russian travellers on domestic flights made of this. So they came back into my regular orbit. One Saturday morning, we were boarding at St Petersburg to head back to London, and surprisingly just the front row had been wound to the old C class configuration. Anyone who eyed these as they boarded was shooed past by the flight attendants, in their notably stylish new pale blue uniforms which Pulkovo had done by a Paris fashion house. When all seated, in comes the Governor of St Petersburg, Valentina Matviyenko, in those days about No 8 in the Russian political hierarchy, who took her seat at the front. You know craning of necks from down the cabin when someone prominent boards. That was there. And then the otherwise redundant green curtain was pulled across, and on we went. Just 4 premium seats. And one such passenger.