When your car is basically the way you want it and you can't find anything else to do to it; you rejoice when you discover something like this. The keyholes on rx7 doors have a plastic flap on them. Over time this flap gets brittle and falls apart leaving an exposed hole. Something like this.
It's also common for the surrounding face of the key hole to be scratched up from non-car people trying to unlock the doors. Fortunately jza80 on Norotors.com sells a repair kit. It consists of two new plastic flaps, two replacement springs, and and two new surround faces. He had my kit shipped out the same day I paid.
I just finished installing mine. The door panels do not need to be removed for the install. I'd recommend rolling down both windows though, and laying a microfiber towel in the back of the window opening so that you well have a resting spot for the lock assembly without risking scratching any paint. Then you can pop off this cover inside the door and remove the two 10mm nuts. Don't be surprised if the studs come out with the nuts, mine did. It's no big deal, just pretend they are bolts instead:)
Then on the outside of the door you should be able to pull the lock assembly panel outward some. There will be a metal rod for the lock assembly and a metal rod for the latch assembly. It's tight but you should be able to unclip each rod. Then you can roll everything face down on your microfiber towel.
Now you can work on removing the lock assembly. It's held in with a metal wire you have to pry off each side. Afterwards the lock assembly will slide out. There will 2 wires that clip to the back of the lock mechanism. I left this clipped for the drivers side and did the rest right there in the window opening. But on the passenger side it unclipped itself and I was able to remove the lock assembly completely. That may be the smarter thing to do because then you can bring it to a table or workbench.
Remove the outer chrome ring on the lock assembly. There are two little tabs that bend in. On the drivers side I was able to just twist it off. The passenger side was stubborn. I had to pry at the back side of the metal tabs slightly deforming the inside edge of he ring before it would come off. With the ring off you can pull off the face and it will look like this. There may or may not be old flap material and spring in the lock. If so remove it.
Here is a shot of the old spring (top) vs the new spring (bottom). Even if I wanted to use the old spring I couldn't. It was weakened/deformed/bent. I tried it and wouldn't put any tension on the flap to hold it closed. So I'd plan on using the replacement springs.
Install the new spring, the flap, the new face, and the outer ring. Make sure the smooth side of the flap faces outward. If you had to bend up the outer ring to remove it you should bend it back into circular shape and bend the tabs back in a little ahead of time. It's quite challenging to re-assemble. You'll have to hold the spring and flap down and press the face on quickly. It will make you appreciate the difficultly that Indiana Jones overcame when he performed the Idol swap. On the pasenger side I used a small screwdriver (if it's sharp put some masking tape over the end) through the key hole in the face plate to hold the flap down while I aligned the plate.
The drivers side will have a small light bulb. You may want to check that to see if it's burned out. It will light up the key hole at night. I'm not sure when or how. There is no socket for the bulb, it's attached right to 2 wires that go down into the door. Fortunately mine was still good so I didn't have to do anything with it. Reassembly is the reverse of the install. This is the end result. It looks good and works as it should. Time will tell how long the plastic lasts. Hopefully a long time.