Not to long after I unleashed PIvena on the world I updated the design for B+ support. The thingiverse link for the project has all the files. I had to move the LCD button board to the other side of the case, added (2) 1/2" screws and nuts and changed the cutouts for the B+ peripherals. Otherwise it's the same.
I had a special request for the original B version of the PIvena to support the earliest of B boards, which didn't have screw holes. I'll admit I was a little bit late to the Raspberry PI scene - I didn't realize that a board without screw holes existed. I created http://www.thingiverse.com/thing:502521 to allow you to fit a non-screw-hole Model B in the PIvena. Just print it out and you're good to go.
Shamlian on Thingiverse made a super-sweet PIvena out of black acrylic, but he really stepped up the whole thing by adding the guts of an 18650 cell power bank. I've been thinking about doing the same thing but haven't gotten around to it. When I do I'll post an update and link to the design files.
I know there are atleast 45 PIvenas out in the wild. If you make one I'd love to see your build and learn about what modifications you make to it, so please share!