Walter.
I remember these kits. In fact, HP had 2 different kits. One for the 5L/6L, the other for the 1100. I ordered two of these kits for myself for curiousity sake. Never installed them, but then again, I was very familiar with the disassembly of both these products. So, I typically just replaced the sep & sub pads as needed. It gave me an excuse to tear apart the printer, and give it a good cleaning.
These kits are no longer available through HP. In fact, I don't even know where mine went. I've moved a couple of times since I recieved them. They're probably in storage somewhere.