Hi Bob, I have just started a remodel here and have existing cast iron base boards. My house was built in 1953 and here is how it was installed. The base board had no drywall behind it,,, just a layer of tin foil for reflection of heat. The drywall ( 2 layers of 3/8" ) sat on top of the units to give it a more resessed look. My idea for where I'm doing changes is to use 1/2" foil faced sheating from the floor up about 9 inches than drywall above that. I too have been looking for a place on-line to purchase the Weil- McLain to save a little cash,, but it looks like I might have to go to a local supply house and order it.