5K Ignition Switch

[Mark and Aviva Woodland]

Greetings listers.
After putting up with an ignition switch that just got progressively worse,
i.e. we had to jiggle the key while in the start position to activate the
starter, I replaced the electrical half of the switch. No good- no bueno,
outright or partially. The symptom persists... but at least its good to know
that the electrical half is new...and I did replace all of the burned out
bulbs in the instrument cluster, which made the whole exercise (almost)
worth the price of admission.
I searched the archives and found plenty of questions (same symptom as
above) but not much in the way of answers, save for the "add a relay and a
hidden remote switch" fix, and I already have the hidden headlight switch
(factory fog), and hidden dimmer switch (under the carpet) and semi hidden
cold start override (dangling from beneath the dash).
What's the real deal? Is the mechanical, keyed half of the switch to blame,
and is the only recourse to replace it?
Thanks in advance for your help.
Mark