Yes DB
(BTW what is your real name?),
That is possible, both locks can be dismantled.
Fuel filler cap:
Remove the outer assembly first. These are the zink-plated part(s) that hold the cap in the fuel filler neck. It's pretty forward how that works.
Then remove the gasket of the ff cap. Underneath you will see two little holes, approx. 3 mm diameter. In one of these noses you will see a little sheetplate nose, which is spring-loaded. Push this one aside with a nail, needle, little screwdriver or so. While doing so you can prone the chromed cap off the inner part. Inside you'll find a coil spring, a lot of dirt and old grease. Wash it off with some gasoline. Eventually you can see a little snap ring, which needs to be removed. Keep it well, I have not been able to find these anywhere yet. After removal of the snap ring you can take out the cylinder lock mechanism - best is together with its key.
Now whash everything carefully with gasoline and you can send the outer cap for rechroming. A while ago there were quite some of these chromed outer caps on ebay for very reasonable money (about 25 Euros) but I haven't seen them in a while. Furthermore, the lock cylinder fits in those ones very, very tightly ...
The trunk lock (outer part, chrome assembly) disassembly is easier.
Take it out of the car, the biggest problem are the two short screw studs, which easily tend to brake when you try to unscrew the both 10 mm nuts with which the whole assembly is fixed to the car's body. Use a lot of WD-40 and be patient. It's well worth to wait.
Once out of the car you should clean everything with gasoline again.
You can now unscrew the angulated diecast "finger" that pushes the inner trunk assembly (visible from inside the trunk)with a Philips screwdriver.
Again there is a snap ring or retainer visible, which is fitted into a grove within the trunk lock assembly. Once everything is cleaned you will easily detect that one. Take it out with a little screw driver or so. Some tinkering might be necessary but it works well.
As far as I remember everything should come out then.
While the outer chrome part of the lock assembly can be easily rechromed, the inner part (the lock cylinder), which holds the lock mechanism (where the key goes in) is much more difficult.
Often this one is heavily rotten. It is then better to look for another used one... I believe the cylinders of a W110 (or W108) sedan should work.
Sorry I have no pics about the disassembly.
It's also worth to search our database here, maybe some pics are around there.
Good luck !
Achim
(Magdeburg, Germany)
