I used a Diablo aluminum blade and cut the standard case in 1/2. The blade cut the case like butter and perfectly square. I had to do a very small amount of deburring with a fine file and then finished the new edges of with some black paint. Other than size you can't tell the difference. Everything for the clock fits in the 1/2 case. I'm not finished. I'm waiting on a 3mm tap and I want to mount the 5V supply before I do the final wiring.
Note: You'll need to tap (4) 3x0.5mm holes in the case halves for the end plates (two top, two bottom).
:/ I don't understand why image tags aren't available. Whatever... Here's the uploaded image.