Jeff Liebermann wrote:
A past owner had embalmed the printer in layers of bumper stickers, pogs,
labels, and rubber cement. Most of this was removed by the vendor, but
I think he just gave up trying to clean up the printer.

I've tried alcohol, paint thinner, Goo Gone sticker lifter (citrus
power), Oops! remover, WD-40, ammonia cleaner, and 409. All of these
soften the gum and goo to various degrees, but leave enough imbedded
in the textured plastic surface to make the printer look filthy. I
hesitate to try a stronger chlorinated hydrocarbon solvent for fear of
destroying the ABS plastic.

I don't know if it harms ABS, but I've removed adhesive from ABS with
waterless hand cleaner, like Gojo or Goop. It takes a few minutes to
soften the glue.