It is clear that the set adjusting was cheapened for the Model 430. ... But your machine - the Model 590 - had a proper adjuster.
Amazingly, ODK does not have a 590 Operator Manual! We only have a Spare Parts List. Amazing!
I attach the required pages (see gallery). Adjustment of reel to bottom blade would be via the "soleplate adj screw" [No 28]... p/n 591584.
I think the soleplate pivots on [24] and [25]. You would need to loosen the set screw [27] and then adjust [28] to close or increase the gap between the blades.
Once adjusted, the set screw [27] would be re-tightened to hold the set in place.
However, your images are small and lack resolution. the reel and bottom blade look blunt! They need sharpening.
I thing a 'set' would be useless if the reel is blunt and the bottom blade is worn beyond serviceable life.
I hope this helps. but your post has highlighted our ignorance of the Diplomats and the differences between the 590 and 430.
Please keep us informed.
Cheers ------------------------- Jack
p.s. higher resolution images would help blade condition assessment.
