Book states 1830 high with rails, I suppose it's how much extra room they allow, it's not as if they max is 1800 and anything a micron over will get scratched Former Mod/Member, with the most post & Chicken George Arch nemesis

Removed the plastic strip along where the rails are, and found numerous bolt holes to secure things. Currently building something to fit on top of the plastic strip which secures directly into the bolt holes. The "legs" will be the tricky part, the cross bars the easy part.