Hi - Look - the best option is to download the factory manual from this website as they are really VERY good. However - As far as I remember (mine don't have steel gaitors just rubber ones) from other times...
The chrome dust seal holder fits inside the steel cover. It has to when you think about it...
In your picture the forks are not assembled correctly. You assemble the lower legs / dust seals / upper stauncions as a unit. Slip on the springs and the steel covers and you will notice that there is nothing stopping the stauncion falling down into the lower leg and that you can't feed the whole thing up into the triple trees (yokes) and assemble it. With internal springs the preload is set when you fit the top cap - external springs and its set by pulling the staunchion up into the yokes which is why you need the special tool (you can use a broom stick or other bodge but trust me the tool is well worth the investment)
This is for pulling the stauchion up into the yokes.
http://www.ebay.com/itm/TRIUMPH-NORTON- ... 0421371514Basically this kit does most old brit bikes with external springs. You select the threaded plug the fits your fork stauncion and fit it onto the bottom of the puller. Drop the puller through the yokes (remember to fit the headlamp ears) and wind it into the top of the stauncion. Now you can wind the stauncion up into the yokes against the spring and when it fits into the top yoke taper tighten the pinch bolt on the lower one. Remove the puller and fir the cap nut. Tighten the nut, loosen the pinch bolt and tighten the cap nut again.
Do both sides - loosen everything off and fit the front guard and wheel loosely. Bounce the whole plot up and down a bit to aline everything and tighten from the bottom up. Once its tight try and see if the front end will move smoothly. If not somethings out of whack or maybe the yokes are twisted. Onces its right - tighten again..
Note I assume the steering head bearings are 'set' first but best to check em again....
This is for fitting the seal holder (chrome thing) and well worth it too
http://www.ebay.com/itm/Wrench-fork-sea ... 0960232059