66 dart LED prototype working for now

You could also consider back to back C's instead of D's. The D's would drive me nuts also
I was tinkering with that and ended up liking the design. (still have to see what it looks like) . the Wife likes this one better that the double D's too! here's a bottom view of the pad design. just a little more work to do for the holes
View attachment c-light righ inner.jpg
I'm still waiting on my led's to come in but I'll etch up a board, can't use prototype board on this one. spacing is all over the place on this board and on the Double D one too!