The way I remember it is if the top link is shorter then the front wheel is forced forwards and that gives less trail. It does not help with exact dimensions but at least one knows which should be long or short.
will keep going thro what i have bought , its in boxes and is looking like a very expensive long project , what i dont use i will sell .
The links on a Vincent do not have Brampton marked on them.i have others so will go thro but these are the only ones marked brampton