Hot Rods Steering box id , F1 variation?

The steering box looks like an F1 box (RHD version) but I cant find any info or pics with this type of sector shaft adjustment. Looks like the only adjustment is to take out end play.
Thoughts anyone

 

Got me bump up....

 

Drag on the worm gear and sector is adjusted by shim/gaskets on the end cap. And as you found out, the clearance to the sector is adjusted on the side cover.