I needed an increase in the compound slide movement without major effort, This was resolved by simply adding a spacer block, see photo.
A 20 mm increase seems a small amount however its essential if you require an interrupted straight run. The material in my case was Bright mild steel 20 x 25 mm x 85 mm long, machined in the same profile as the upper slide. For other machines the sizes will need to be measured / calculated.
