Braille alphabet decoder (attempt)

My attempt at a credit card size Braille alphabet decoder.  I don't know if it is technically correct or how useful but I tried...

Not a perfect design and I am not sure it has the right scale (may be too small) but is mostly satisfactory (to me) and could be useful reference or to be improved since code is included.  If I have some more bandwidth I may try to improve this code myself as I learn more about Braille but no promises.  This is my first attempt at this.

Notice the repetition between the first 10 characters, the second 10 characters, and the remaining 5 (excluding W which doesn't conform to the pattern).  A-J use the top four dots (1,2 on left column and 4, and 5 on right column).  The next 10 characters are the same except for the lower left dot (position 3) is added, and most of the bottom row characters (21-26 excluding W which does not conform) have both bottom dots present (positions 3 and 6). 

Braille numbers representing 1 through 9 and 0 correlate with A-J respectively.

I am just learning.  There is more to Braille than this decoder shows the basic alphabet as I understand it.

I am printing one now at 0.12 layer height.  If you can improve it, feel free to make it better and remix.  I included the openscad code used to create it. 

There are recessed letters under the braille but the rendering is not showing it quite right so the code could be improved.  The recessed letters seemed to print faintly for me and are basically flat.  Again, not a perfect design but may be helpful or improved.  I hope it can help people learn/remember Braille.

Feel free to make it better and more useful!