There was someone on here selling them, someone also made some from cutting up some pipe. I have a shop saved somewhere that sells the spacers, 8.1 length or something like that, a few cranks use them, i will try to find it later for you.
8.3mm chainring spacer for inner position. Machined to close tolerances out of 6061 aluminum. Excellent for improving chain line, or for replacing missing spacers. Inner Diameter: 8mm Thickness: 8.3mm 20/bag