The Roke Mead bonus cache is a medium sized container, there's room for swaps and trackables, pen has been included.
Hopefully you have enjoyed the stroll and have collected the required clues. Once you have jiggled the numbers into the below formula you can take a well earned rest and go for the bonus.
N50 41.X(R+F-K)(Z+R-4)
W001 09.(B-F)(R*K-1)(Z-K-1)