i have watched locksmiths open up ignition locks..... NOT the switch.... before to reset the tiny tabs. this is done to permit the key to a specific car to now fit the ignition lock which was installed from another car that originally had a different key.

it is actually quite interesting to watch.

from what i understood for instance all volvo 240 lock start out the same. the only difference is the tiny tabs and how they are positioned with the lock.

my guess is while you were making your repairs one or more of these positioning tabs which determine which key will fit which lock moved or fell out of position.

if true unless you remove the ignition lock and actually open it up and reset these tabs or have someone else do it you're out of luck.