yes there are 5 columns in the machine, 2 small (approx 2.5 x 2 x7/8") and 3 larger (3 x 2 x 5/8") and they vend in the order of L,S,S,L,L.
Obviously clever old Mr Brian didn't want every consecutive prize to look the same, might give the game away.
Interestingly chalked inside the back of my machine are the words "Checked ok 3d. W.B." I wonder if he always did a final quality control check!