Don't take it personally Graham, I just giving a general advice.
In many cases the questioner is giving too little details to draw any conclusions and give any advice...There's a number of data that is needed for someone that can't see what you got.
Year model or version is basic data and sometimes enough to state. In this case, a full list of details may not be needed but at least some of- ball bearing hub/roller bearing/new/old parts/measures/arrangements done/modifications/previous problems, would be nice.
At the brake plate side, parts are just stacked and screwed in bottom, so it is a matter of if the parts are correctly combined, if something extra is added or new/old parts are assembled that makes measures wrong. I haven't checked at the moment as my parts is in boxes in my shed, but it might very well be so with all original details put together, that the threaded part on the hollow shaft is shorter than the assembled parts so the nut is sticking out a bit. Then, the rockers lock the nut safely when the wheel axle is torqued.
