front antiroll bar sizes

Well I decided to refurbish my caddy front end, suspension, whishbone, brakes etc and add a front gti antiroll bar. Well at least I think it's a gti one. It's 17mm diameter. And I can't find bushings for it. I need the 4 but when I look they are in 15mm, 20, 24mm … and hardly any for 17.
Do I have a weird version? Where do you folks get your normal standard vw bushings? Thanks for your help.

well ordered a set of original ones, without mention of diameter size. The holes were 15mm … put lots of soap and puched them on anyway. there on. The whole thing is ready for instal.
hope this helps someone else, because looks like nobody knew …