The block has overall dimensions of 40mm by 32mm and is 8mm thick. Each is included with two mounting screws,
either two M3 x 8mm screws
(perfect for use with the GR02)
or two M5 x 20mm screws
(option selectable below). The screw socket size is 4mm. The centre-to-centre distance between the two mounting holes is 32mm.

shouldnt that read either two M5X8mm screws

look good Ewan, though id make those shafts shorter with the thread closer to the bearing....