Calum, didn't you machine washers with a part that went into the sleeve area acting as the sleeve and washer all in one? Pretty nice idea, although the washer and sleeve would turn together.
I didn't machine them, they were supplied with the shocks to fit the bracket sizes that I gave to BG Motorsport but yes they are a combined sleeve and spacer which does make them easier to handle than say putting a sleeve through the bearing and a simple loose spacer each side.