Thanks for the information. Looks like I'm going to have to cut thru the stainless steel on the back of the hood to create an opening. That should be fun. I guess Duct Tape will have to close the gap between the hood and the exterior vent. I first noticed the missing vent when the smoke detector kept going off when cooking even with the exhaust fan on. Well, no wonder! Now I just unscrew the smoke detector and turn on the Fantastic Fan when cooking anything on the stove top. I like the idea of clear silicone to stop the rattle of the plastic cover while traveling. Thanks again all.
—Gary