sorry for being late with the info, had busy day with my family celebrating my mum,s 80th birthday
measurements for you......
the CP15 plate that is on the outside(offside) is 120mm from the inner edge of TR2 along the TR9 rail, then you have the 40mm width of CP15 then a 60mm gap to the next CP15 plate.
i hope this makes sense & hope it helps
cheers
andy