I have a Sportsman kit on my '54 (it was on there when I
bought it).
See:
http://www.havasreti.com/images/sportsman_speeds.jpg
I have trouble believing a 4mph *increase* in cruise speed
as a result of installing the kit (?). The kit increases wing area,
and therefore drag. I might buy that the cruise speed is not
affected an appreciable amount (in other words not degraded)
but increased...?
The landing speed with flaps 40 I might buy (slowest I've approached
is 45mph with calm winds). My '54 quits flying at 35mph indicated with
flaps 40.
The takeoff speed with flaps 20 of 40mph I might buy also (I've
hauled it off with flaps 10 at 40 indicated).
The rest of the numbers I haven't measured / tested myself so have
no way to know if they are accurate or not.