After looking at the post with the Beli truck I started to look and look and here is some info. Guys name is Clayton Holbrook. Seems that the idea did not float or this would be one heck of an idea.
patents www.google.com/patents/US20040200361 www.google.com/patents/US7011859
The way to core the middle is with a stainless steel cylindrical (serrated edge) drill bit. He also uses a vacum to suck out the inside of the bread while its being cored.
The other problem I see is the way he puts in the filling. He uses the some type of food grade plastic sheet he calls the carrier sleeve. That then gets two plastic rings on each side to hold the content together. He pushes the content in (what if the bread breaks??) then hooks up the plug to the extractor and its done. Still makes me wonder if those plastic rings could end up inside while he takes out the sleeve.
Anyways, I would like to expand on this idea. I have been calling him but no answer. Its like he dropped of the face of the Earth a year ago.