Welcome to TruckNet, Speedway.
…You might be better off asking this question on the forum below: ‘Old time Lorries,Companies & Drivers.’ 
This new and wannabe forum tends to cater for mainly new drivers who don’t have a lot of experience of ‘any’ gearbox patterns, never mind one from over 20 years ago! 
(No offence, Boys & Girls -we all had to start somewhere.)
Over on the Old time L,C&D. forum the posts are viewed by far more of us Old gi…,er, more mature drivers, who may know the Fuller (smooth-as-butter) gearbox from all those years ago.
I myself drove a DAF 2800 DKS for a time but I’m sure I vaguely remember that had a 13 speed Fuller not a 9 speed. The gear lever had a flat top and a 3 position switch at the side and the change pattern involved a ‘u’ somewhere - was it bottom left to bottom right then top right? - to be honest I can’t remember, it was that long ago! You only needed the clutch to start off, and once you got used to the technique, it was a nice smooth and easy drive.