jimbeetle - 5:31 pm on Jun 11, 2013 (gmt 0)
If you do b) Google says "Hey this page is GONE I better remove any links, but I'll still hang on to the page content just in case."
Yeah, Google does like to hang on to stuff, but that does not mean keeping things in its index if not necessary. If you click the link I posted above you'll see what Google's John Mueller has to say about 410s.
It's a simple process that seems to have become complicated in this case. All you have to do is return a *valid* 410 response. There's no need to muss around with robots.txt because if the pages are gone, well, they can't be crawled.
What I was trying to get to when I asked "Exactly how are you serving the 410 status?" was technically, exactly how are you returning that response and that's because way up above you seemed to conflate robots.txt and server responses:
To be clear, robots.txt is correcly disallowing any crawling on widgetworld.com (the bogus domain). Apart from robots.txt (200) it has been 410'ing all requests for anything some time.