MakerSlide is not here yet, but the day is still young.
In the meantime, these arrived from the States. They are stainless steel precision washers, 1.00 mm thick, 5.00 mm inner diameter, 7.70 mm outer diameter (actual measurements 1.01 mm, 5.05 mm, 7.72 mm, with less than 0.01 mm variation between samples). In addition to the increased precision, these have a major advantage over our old shim washers (and over those from Inventables, which are 10 mm outer diameter): they can not touch the bearing shields, because they are no wider than the inner race of the bearing. This will reduce the chance of problems caused by shields that aren’t recessed enough, and eliminate one source of frustration when assembling your eShapeoko.