An update: I tucked the ATSC receiver inside the cabinet, and added an extension IR remote "eye" to the front of this "set". I scrounged an IR "eye" from a dead cable box, and literally soldered it in parallel (with about a foot of shielded 2 wire and ground cable) with the existing "eye" inside the Samsung ATSC box. Well, it worked. Occasionally, hacking around does work..
The IR eye has three leads, a ground, B+, and signal out that feeds a digital chip. Must be an open collector pull down sort of thing, as having two in parallel didn't burn anything out, and it still works. All the front panel controls of the ATSC box are also on the remote, so I didn't need much worry about them being inaccessable once I mounted this box inside the cabinet, with a couple sheet metal screws into new holes on the removable top lid of the box. And there's on screen display of channel numbers.
So now this thing is a complete HD TV... But it still looks like a monitor in a TV cabinet...