I'm going to guess the last successful airliner without a computer was
the Boeing 737 original version. And the largest sucessful airliner
without a computer was the Boeing 747 original. And I believe the last
successful large bomber without a computer was the B-47. Can anyone
confirm or refute this?

In particular, no internet source says if the engine controllers were
mechanical or computer.

Definitions:
There can be no necessary computer at all. Not in the engine
controller nor in the flight controls. If there is a computer, the
plane should be useable with that computer turned off.

A computer is an electronic machine with a CPU, RAM, and software.
Mechanical computing devices do not count for this exorcise (though
they are interesting).

-Curious
-Kitplane01