Well, a single coil cover can be easily changed; the ones with the company logo are just silk-screened "normal" style single coil covers.
On a humbucker, get scrubbing. I have a Jazz neck that was apparently scotch-brited/relic-ed to get the logo off, but you can't switch bobbins or fit the cover from a single coil. There are also stickers to cover them, and I think some solvents work, but those are your options. It only bugs me if my pickups don't match; all Duncan or nothing for me.
You can use your old non-logo covers. They're not held onto the pickup by anything; when you unscrew the pickup, they'll basically fall off, just sandwiched in there.
Hi. Can the SD logo be scratched off easily without harming the pickup so that I don't give a dead giveaway that my pickups are duncans? If not, would any old single coil pickup cover work to replace the cover with one without a logo?
What do you mean with "often"? Unless it's the Vintage Mini Humbucker, if the p'up has a golden or nickel cover, there won't be any logo, period.Why is it that the famous artists who use Seymour Duncan pickups often don't have the logo on their covers?