Well, I can only speak for myself, and I have had runs where I haven't gotten a single kit in probably a couple hundred quest iterations. Then there are times when I get 2 a day. Perhaps other people have been more lucky, but if you are looking for heartwood kits/saws in particular and are holding your breath, my advise is just start breathing normally because you are going to be questing for a VERY long time, so just breath!
If you have only been running this script for a few days, you'll just have to keep at it. I guarantee the kits will be looted, however if you are in felucca, you do have to be careful about thieves.