Thanks for the info guys. I have a few links from my previous run through with this process, but those were boxes that were fairly fragile, especially the thin ones (7mm & 5mm). I have a ton of movies that have just been sitting, taking up way too much space in their original fat (14mm) boxes. A perfect exampls is the MAMMOTH box set for Space:1999. Something like 14 discs - each in it's own 14mm box inside a thick cardboard presentation outer case. I could literally put everything in 1 14-disc DVD case that's only 30mm thick, about a 90% reduction!
Another roadblock has been the software I use to make tweaked sleeveart to fit the slimmer cases. Recently, I replaced my aging computer with a new one that uses Windows 8.1 which is pretty nice; certainly processes waaay faster than the previous system. The software of choice I've been utilizing up until now to make my DVD cases is an ancient copy of Adobe PhotoDeluxe 3.0, which came with the first home computer I ever bought, way back in '98. Sadly however, this new system won't suport it so I am forced to chug through with photo software that's far more complex than what I really need - or want. Granted, PD 3.0 wasn't anywhere near as powerful as the newer Photoshop offerings, but it was perfect for allowing me to quickly and efficiently whip up replacement DVD artwork with custom, narrower spines - to fit the slim & super-slim boxes I was replacing the fat stock boxes with. Adobe's Photoshop Elements is slightly less cluttered than thier uber-complex Photoshop, and a little more streamlined, but still waaay too overcomplicated to just tinker with. I suppose I just need more seat time to get familiar with it? Oldfart syndrome, I guess. SIGH.
While I'm at it... any recommendations on websites with custom DVD box artwork and also... quick formatting programs for generating custom DVD artwork????
I most often try to keep the front & back stock art/info from the original boxes, but sometimes I like to customize, (2008's DVD art for "The Incredible Hulk" is a perfect example. I hated the DVD art but loved the theater poster so I made my own jacket art). I especially like to use original poster art for my DVD boxes with older, classic movies. Many pre-80's era movies have some truly awesome theater posters and lobbycard graphics that make for really sweet DVD covers, (Inframan springs to mind), and they are often lightyears better than the hideous, crappy looking photoshopped covers that a lot of companies use for DVD box art nowadays (the recent BenHur remastered deluxe Blu-ray for example). Anyways... it's late, I'm tired and apparently more or less just rambling now...

Thanks again for the weblinks gentlemen. I will check them out!