So you have everything you need (reagents, equipment, technical skill, knowledge) to perform a re-dox titration. So the question now is: will anything in picked lime cause a problem? I don't know. Try it and see. If you get no result, try spiking in some vitamin C standard, and see if you still get no result. If so, then something in picked lime is blocking the reaction. If not, then you know there isn't any vitamin C left over after pickling limes.