I have lifted out my keel many times but I din't count on the wire strop to hold it.
Support the keel from the underside--perhaps a beach or concrete hard----then unscrew the keel box-- open and you will be able to attach to the lifting line---for safety you can attach a line to the keel pin hole.
I never did trust the wire strop because i is designed to stop the keel from falling through while in the water--so it really has little strength compare to the lifting line--since the keel is bouyed up by the water.
I change my lifting line every 3 years-- never a problem and always sprayed the keel slides and the blocks with Harken sail slide or a good waterproof lube.
I do need the measurement of the wire cable but if I can get it from the top of the keel box while the keel is pinned-- to the washer/crimp on bungee up the mast. That would be terrific.
Thanks, Marv
marv Kowalewski