Leaking Thermostat Housing. Thinking on billet with O Ring

Update. No more Leak. Here is a copy of the Email I sent to Billet Specialties:
"I bought your Mopar billet thermostat housing for my 69 340 motor. I have been fighting a constant dribble from the base of my made in China chrome housing for years. I tried EVERYTHING. I went through so many gaskets, I was about ready to buy stock in Felpro. Your housing finally fixed my problem. I used a flat file on the intake surface like the guy on your tech line suggested. Thank you for producing such a fine product at such a reasonable price. I will definitely buy from you again."