4-Door with 340 from the factory?

NOPE !! In North America.

there may have been a Swiss built 340 Monteverdi 4-door in the mid 70’s. I know there was a 360.

This! None documented in the U.S. and not sure there were any in the world, but Steve may be right. Funny they put Hemi's in 4-doors and wagons, and maybe a CSS truck (one claimed but not proved) but 340's were only in "muscle" cars...