I've still got my old set kicking around because I think 3 of the 4 were still okay, but figured they would still be worth hanging on to for a "just in case" scenario. I thought about trying to rebuild them as a side project as well just to have them around if I wanted to go back to a stock setup. Doubt I ever will, but I do like having them around for peace of mind. Can't remember who actually made them. I know a lot of OEM setups are basically really designed by aftermarket companies, just with labels removed, so tracking that down would be a good start. Guess they could still be KW like the ACR ones. Will have to look at them closer one of these days.