Virgo, you should be able to get the basic `clean` stalling speeds for the two weight conditions,as that is the `basic` point for L= W., from your POH.
To relate that to T/O,you must be in the same configuration,vis-a-vis flap/slat settings, otherwise your Cl will be different; nearest approximation for T/O would be the Vmus( minimum unstick speed- rotate early ,scrape the wear block on the tail, until you get airborne), which the FAA/CAA all require for certification..... ; or have I now dug a bit of a hole...............?..Syc..