Found it!!

Just a day ago I asked about a science-fiction short story anthology I had as a kid, the title of which had been lost to me for decades. 

It took a reader on Sci-Fi Stack Exchange all of about twenty minutes to give me an answer. 

Beyond the Stars: Tales of Adventure in Time and Space not only included the only known excerpt from the original Star Wars novelization, it also had an excerpt from a Doctor Who novel, a fact I had completely forgotten but that roared back with full clarity once I saw the table of contents. It also had a weird combination of Star Wars cosplay and Battlestar Galactica Vipers on the cover!

I found a copy for under six bucks on Ebay (albeit with no cover photo) and ordered it on the spot. It'll be good to have it back "home" on my shelves.