I wanted to share this because it's such a simple fix and made such a huge difference - I can lock my car now!
I just finished rebuilding the driver's side door handle on my '66. That wasn't the plan going in, I was just going to replace it with one I picked up from JW yesterday that included a key. My car's ignition key didn't work in either door handle or the glove box, so I figured someone had replaced the ignition switch in the past and lost the key that fit the doors.
WARNING: of the 3 door handles I've got, 4.5 of the 6 studs are broken off or missing, so I'm thinking this is a fairly common occurrence and it would really suck if you broke them. As it was, the original handle has 1.5 studs...one complete and one half stud that's only useful as a locating pin. It's always been like that, so that's what I stayed with.
These aren't like the lock cylinders in Wayne's in 101 Projects re-keying chapter, so you don't have to worry about tiny pins & springs sproinging into another dimension. These things are so simple you could easily rebuild one to like-new functionality in 15 minutes, not including door panel removal. If I had known when I started what you're going to find out now, I'd be on my third beer instead of my first.
The problem wasn't the key, it was that the lock mechanism was so gummed up with old grease, it was essentially frozen. I'll bet a lot of keys have been bent or broken because of this.
Here's a complete door handle w/the lock assembly (note missing studs).
Here are all the pieces (this is a different handle...note missing studs). Everything is indexed, so you'd have to work at putting it together incorrectly.
First, remove the screw and pull off the door lock actuator (the cam looking thing with the peg).
Remove the spring (note position). The lock actuator has a tab that fits right in-between the two spring ends.
Pry off the 3-pronged washer. There's a tab on the washer that goes into a keyway on the push button.
Remove the circlip. Upon reassembly, orient the circlip so it doesn't cover the keyway on the push button.
Remove push button (note spring).
Remove lock cylinder from the push button by pushing on the inner end of the cylinder (the square end that the actuator screws into). Note orientation of the cylinder in the push button...the cylinder pins fit into a channel in the push button.
Now, clean the old grease off everything, including the insides of the push button and the hole in the door handle. Grease everything up and assembly is the reverse of disassembly. I also sprayed some Gibbs on the all of the lock mechanism pivot points inside the door and hit the remaining handle stud with some anti-seize. I love it when a plan comes together better than I anticipated!