leaking T-stat housing

I just re-did my thermostat housing. I purchased a new chrome housing, sandblasted and powder coated it. It started to seep so I installed 2 gaskets. It held for awhile but started leaking this winter. I took it apart and checked out the mounting surface. Whoa! It was warped badly. I used a large sanding belt to take the warp out of the housing. I then had to maching a new groove for the thermostat. After doing the machining, I re-installed the housing with a single gasket. It works great. No more seeping! I think I will get another housing and machine a groove into it for an O-ring. I know this is what the Chevvies do. Seems like a simple task to keep this housing from seeping. NE1 done one of these with an O-ring?