Well recent I ran across some good photos of the actual studio filming model that almost was the Millennium Falcon. It featured most of the same details I mentioned, originally designed by Ralph McQuarrie, but had some differences. I had some spare moments, so I knocked together some details lifted from my other Falcon model, to get another look at the Falcon that Almost Was.
This is a rough draft, without many greebles, but you can get the idea. I've also included some shots of the real thing.
Here are some interior renders, based on Production Designer John Barry's sketch of this ship's interior.