Hi Albert
Personally I would imagine that .5mm shorter on the bush tube is way better than being, too long
As long as you can bolt the assembly up tightly & have no undue play it should be fine.
If needs must, you can file a fraction of a mm from the crush tube .... The suspension bracket will soon pull in a tad
I know you had great difficulty getting hold of that tube .... I have a few spares that are machined within .01mm if you are desperate for a few
