When you are done drawing the wrenches, draw in lines for the ruler and check the scale of the drawing:
Doing the math we get:
140/140.496 == 0.99646965
So select everything and scale thus:
and the size is pretty much as desired:
Attached. wrenches_redrawn.c2d (15.2 KB)
and the SVG: wrenches_redrawn.zip (953 Bytes)