Is there a way to remove them without damaging the case?
Maybe sliding a putty knife under the wood near the nails and prying up, then pushing the wood back down will leave the nail heads up high enough to grab them with pliers?
In a word, no.
I use an itty-bitty screwdriver to get a little lift on one side, then the other. Then I use an itty-bitty pair of side-cutters and carefully pull the nails out. There will be a little scuffing, but I generally sand the sides a little anyway (sometimes a lot)...
: ^ )
I like Marks idea the best. The best part is after they are in the car, you can see them.
If the nails are rusted it is impossible to get them out without some wood damage. You can drive a putty knife into the side of the door and remove it in several pieces. This works well if the door is sealed close by the internal tar or someone "rebuilder" in the past has sealed the coil shut with shellac or wood putty. I save the sliding doors from bad coils.
Marks method can work under certain conditions, but be very careful or you can easily tear off the top of the sliding door groove. In my experience, Keith has the best overall approach. Get a set of very small sharp/pointed PC board side cutters. This approach usually results in the kind of minor damage (or less)you see in your photo above.
I am no fan of sanding coils. It changes the external size of wood cases. I have found cleaning the wood coil cases with lacquer thinner is best overall.
I would much rather work on coils that have not been worked on by others as repairing previously poorly executed work is a real pain.
Ron the Coilman
I do as Mark described but use a utility knife instead. Makes it easy and doesn't crack the wood.
Find a tool like jewelers use to pull the hands off a watch. I use to use them a lot when repairing dial indicators and dial calipers.
On eBay, it's called a watch hand puller. Very inexpensive.
I seldom find any that a couple more gouges would even be noticed. I pull mine with a tiny pair of dykes and usually try to turn them to 90 degrees so they will more easily go deep enough into the grain to grip the nail head. In other words, I scar up the wood above and below the nail, not to either side of it.
I do sand mine, but only by hand with something like 120-150 grit paper. I'm not looking to remove any scratches in the wood. I'm just getting the dirt/grease/paint/sharpie marker/etc off of the outside so they will take a coat of linseed oil.
I think I will give lacquer thinner a try. I always use mineral spirits to wipe them down after I sand them. Maybe lacquer thinner will save me a step.
Some light sanding will be necessary to dress off the high spots, especially on the narrow sides resulting from warpage/wet wood..... so the coil will fit in the tester fixture and the car's coil box.