Right, so i've gone and measured with a tape measure, to get 7" inches across and 21.5" inches longways, thats without taking the centres into account, the bolts are M10 so minus the radius of both those holes, is 7 inches (177.8mm) -10mm would be 167.8mm between centres.
For long ways of 21.5", just doing the same 546.1mm -10mm to give 536.1mm between centres, there was a beam in the way with this one so i'm a bit unsure about how accurate thatll be.
Hope that gives you a ballpark.
Michael W
Edited By Michael Walters on 25/07/2016 15:49:56