Except for stopping harmful corrosion or removing grease or harmful substances; I do not invasively clean off other patina on parts because patina is very important to some Buyers preferring to either leave the full patina on or cleaning to whatever degree they desire (usually to match the condition of the guitar they are using the parts for).
The beige paint can be very easily stripped from these tuner keys. These keys would clean up very nicely should a Buyer desire.
Nylon ratchet ties in the images below are to keep skate key tuners held together; Their mounting screws are what otherwise holds them together on a guitar.
ALL of the parts in skate key tuners are interchangeable and there is no specific up or down or left or right part. The parts will all fit in opposite holes in the casings to configure a set left or right handed or dual sets for 12 strings or 3 + 3 sets.
Skate key tuners work remarkably well for their design, if operated properly; ALL old tuners were of a jam gears design which is a slight offset of the matching gears ramp pitch that tightened the gear mesh as the string tension increased. Such old tuners should be first tuned flat and then turned UP / sharp to the correct note to set the gears jam leverage geometry which holds that tuning tension tight; Tuning DOWNWARD loosens the gear jam function, which allows string tension to rotate the strings shaft into gear jam, which of course loosens / flattens the strings tuning. To trim a string's too-sharp tuning slightly downward you simply stretch the string with your hand a little at a time or tune back down below the note and then tune upward again; Not difficult for Players who know and are used to using cam-jam tuners properly.
The most vulnerable part of skate key tuners and the most likely to wear out first, and should be inspected from time to time, is the spider geared sprocket on the end of the strings shaft. If they haven't been lubed with some grease (lithium is proper) from time to time the spider sprocket is prone to wear out. You can get a good idea of the amount of grease still in place in a tuner set by loosening the mounting screws slightly and prying the nylon end-cap off to take a look at the 2 tuners closest to the casings ends. See a pic of the end cap removed further below.
Purists will probably want to check their skate key tuners before buying replacement casings, to make sure they get the right / accurate set for their guitar; There really is 2 different kinds: Nylon end caps are by far the most common configuration for skate key tuners, which was a production-line improvement over the early version that had end tabs of the metal casings bent over to close the ends of each of the 2 casing halves. Both types are shown further below. Leave it to Nat Daniels' production genius, he soon realized that an easier and cost saving method of cutting casings from the long pre-machined casings stock, was to cut the ends of tuner casings flush and left open; Then the simplest of stamped-out nylon end caps could be pressed in to keep dust out and the lubrication grease in, and even allowed for popping the nylon end cap out to inspect the state of lubrication of the gears over time.
Skate key tuners clean up well, like the ones below that were typically corroded but cleaned right up using a Dremel wire wheel and 'PB Blaster' catalytic oil, followed by a rouged Dremel buffing wheel.
Using a brass wool or a well-worn 3M scrub pad to work 'PB Blaster', will also clean up corrosion while leaving whatever amount of vintage patina a person might desire, like the tuners below were (when removed from that guitar of course).
The nylon ratchet ties holding the casings together are installed on the tuners before they are removed from the guitar; By loosening the tuners mounting screws a little which opens a gap between the tuner casing and the guitar's headstock, to slip the lead end of the tie through and close the tie around the casing before removing the mounting screws and tuners; Otherwise the tuners are very prone to spill their guts on your table or floor.
