Anti theft

I have an 03deville my tumbler fell apart and I had
to leave it to get to work.when my brother got there
it was about to be towed.he busted the key switch
to unlock and move it before it got towed. I got a
key switch from auto zone. But it had busted more
than the switch.I went to a pull it place and pulled
new column. I replaced all even the pk3 electronics
around the switch. Couldn't get it to relearn. So I
pulled it back apart and replaced original
electronics with the new pulled hardware. Still
won't relearn. The keys for new switch are not pk3
but I gaff grooves in one and put a chip out of old
key that matches the pk3 system that was working
before still no relearn. What do I need to do it
replace? Do I need a more expensive chipped key
and tumbler or how much of the system needs to
be replaced once a piece of the system is bad