Bruce Deaton does this all the time. He added an outside cabinet and painted the door to match our 2007 Phaeton. It looked like it came from the factory like that.It's an awesome addition if you are a Tailgater and entertain outside.
A friend with a Newmar Essexx had Bruce add this to his coach after he saw mine , and was thrilled
He is in Red Bay AL. The cabinet was purchased from Tiffin Parts
I'm not sure what size TV Tiffin is using on the outside. At the time ours was a 32" , but suspect the new cabinets are designed for a larger TV. The cost was a fraction of what you're quoting . Tell him Mark Evans sent you. (No financial interest , just a very happy customer !)
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