I am going to stop doing this
[Sorry if I am repeating things.]
Have you even seen the P-38M, Night Fighter two seater with a bubble for the backseat
Nosejobs like the Pathfinder that look like someone put a soup can on the cockpit's nose and added windows.
From
https://en.wikipedia.org/wiki/Lockheed_P-38_LightningA P-38L was modified by Hindustan Aeronautics in India as a fast VIP transport, with a comfortable seat in the nose, leather-lined walls, accommodations for refreshments and a glazed nose to give the passenger a spectacular view.
A different way to carry extra passengers, looks like a Med-vac option:
"Want to go for a Ride?"
Here a different one:
Could also use the P-38 kin - XP-49 and 'Big Brother' XP-58.
If you want to increase the cockpit size, a little. Even up to large flying boat size. For multi deck version.