Um - it is perhaps worth pointing out that most light aircraft ASIs really don't have great accuracy at higher angles of attack.
Trying to nail that last couple of mph below the normal stall speed "because you're light" may not necessarily be the best idea in the world.
I would second that. Unless you have the indicated/calibrated speed chart from the POH taped to your cockpit window it is an academic but useless exercise. At those speeds most airspeed indictors are off by as much as 5-7 knots/mph due to the angle of the pitot tube/mast to the relative wind.
At those speeds it is much more about what you as the pilot "feel" through the controls and the airframe then any instrument.
Your "feel' is what allows you to fly in that area nibbling on the stall.