I found a sheetmetal place here in dallas that made a new box cover, out of stainless for like 30 bucks. to hold the pipes up, I made studs by running bolts down thu floorboard, and put nuts on them to keep them there should i ever need to remove pipes. They make a U bracket for electric conduit that you can slide over the new "studs". I also wrapped rubber around pipes where brackets held them up to keep from rattling, and a hole getting rubbed into the pipes. To hold the box on I used short sheet metal screws thu the sides..and if your big pipes are rotten, then your heater lines are too for sure, mine were, little bitty pin leaks, never saw water on the ground, but car always ran hot. BTW, you can still make a cover, just make holes fro the drains to poke thru. Wish I coulda gone stainless, I used 1.25 copper, so far so good, I cringe when i bottom out tho...looks good, with I had drains too!