Hi Mick,
the cross slide measures as follows :
length = 154 mm
width = 65 mm
thickness = 16mm measured where the slide way is and 8.5mm where the dovetail slot is .
dovetail slot depth is 7.5 mm.
dovetail width is 50mm at the widest point and 43.5 at the narrow point
tail stock bolt is M10x 1.5 pitch
the gap in the bed between the slide ways is 26mm
hope this helps!
Ian