All very good replies. I agree epoxy is way to go BUTT. Watch how smooth you get it and keep your paper changed out. If you try to save $ by using paper a long time you actually will get to a point that you are not cutting the metal just more or less polishing it. Epoxy is a strange animal. It's more a chemical bonding product but still needs that mechanical bond you get with a sand scratch profile. Really watch your top coat times. Epoxys are a very slow drying product which is the reason why they (in PPG Products) have 3,5 and 7 day top coat windows depending on not only product but catylist too. I would agree on the Omni/Shopline Epoxy being close to the original DP. Naturally it is lead free too. I have been told the shopline epoxys are a 3 day top coat where as the DPLF 401 is a 5 day but the 402 is an 8 hour window. I have been using the DPLV series recently. Not totally a true surfacer product that's direct to metal but not a true epoxy either. Will actually powder up like a surfacer and not gum up like an epoxy if you have to sand it. Say priming something and getting back on it after the 7 day top coat window. It isn't designed to replace a surfacer but can and does do some filling. It may be worth looking into if you are spreading a project out over months or years. It's not a cheap product but if you figure you put epoxy down then month later sand it all or partially off to continue where you left off its cheaper cause you can hand sand it to prep it for surfacer.