Just get the refills you need. TFtestkits sells them, so does Leslies, so does Amazon. You don't need new hardware or another case, just drops. They're all Taylor reagents. So just match the numbering.
Hey no worries my TF-100 refills just arrived last night and I too waited over two years.
Question for anyone: how do you keep your TF-100 hardware clean now going on a few seasons? Safe to use soap and water to rinse them out once in awhile? Or just rinse with tap?