Ron,
It is very difficult to get any detailed "per coach" schematic information out of Gulf Stream as they claim these to be highly proprietary 'trade secrets' for some reason. I will attach what may help as a representative TV systems wiring diagram that covers some Crescendo models.
I would suggest that your digital converter box be connected at the AVS 100 distribution input for 'VCR' which will allow both TVs to view the content, plus the outside TV if you have one. The antenna input for the converter box can come from the antenna amplifier unit in your entertainment center cabinet (the one with the red light and the cigarette power outlet)
The general coach manual from Gulf Stream is not much, but is on their website and is a PDF of about 950kB -- I can e-mail it to you if you want, just send me a PM with an address.
Chuck