I know you know this, of course, but the LSA stall speed limit is calibrated airspeed.My own Fly Baby is a good example. Everyone agrees it qualifies as a Sport Pilot-eligible machine, and I've been flying it as such for the past 20 years. However, it stalls at about 55 MPH indicated, vs. the 45-knot/51 MPH limit for Light Sport. But the airspeed indicator shows a CRUISE of about 105 MPH, which makes me think the calibration is a weeee bit off.....
My Starduster stalled at 50 mph indicated. No idea how accurate the ASI was, I suspect it read a bit low , but after my accident the FAA never questioned my lack of a current medical.