MarkI hate to be the bearer of bad news but you are still going to need the underdash section that the pedals attach to do it factory correct.
I believe that the automatic frame brace will work for the clutch pedal suspension but has no provision for the clutch pedal return spring to be attached to.Therefore the clutch pedal always hangs low.No spring to pull it back up.
You will also want the collar that goes around the steering collum at the floor.This has a hole thru the collum section to allow for the clutch pedal push rod to pass thru the floor board.
That is where the accordian looking rubber piece is attached as a weatherstrip over the rod.
I looked for a long time till I found the under dash brace.I suppose that a strong bolt could be used as a return spring attachment post as suggested below but thats a lot of spring tension to consider.
Checkout the supplied attachment for the parts breakdown.
Hope this helps,Oldmics