Thanks for the notice on that new Roden "Convairliner" kit. 1/144 is going to be pretty small. Brain calculator suggests a wingspan of about 8".
United flew a large number of the 440 model, to replace the DC-3. The 240 family was the first twin engine pressurized commercial airliner.
We had a grandmother who lived in Solvang CA, about an hour outside of Santa Barbara by car. You would know the area from your time at Vandenberg. We flew SFO-Monterey, then to Salinas by flying east down 68, then south to Paso Robles following 101, then over the hill to the coast and down to Santa Barbara.
The Captain would often fly low over Hearst Castle at San Simeon on the return trip north.
I would think a set for a DC-4 would be a good place to start, those of course being available in hundreds of airlines.
Look forward to seeing what you come up with.