starting issues--ignition switch?

[Blackened302]

alright, guys, i've had enough w/ my car not wanting to start sometimes. here's what i've done so far:

- cleaned starter connections
- tested starter & solenoid
- tested wiring to starter with multi-meter
- new battery, new terminals
- checked grounds
- checked relays

only thing i haven't looked at is the ignition switch/assembly. now, i've pretty much narrowed it down to this, but i don't know which to test: the ignition lock cylinder switch assy OR the ignition starter switch.

can anyone offer ways to test either so i can replace the one that's bad, if it is? thanks.

ignition lock cylinder switch assembly

ignition starter switch