Lo and Behold...
After 3 days and many headaches, the circuit is done.
Inputs A, B, C, and D represent a 4 digits binary number (0110, or decimal 6 on this example).
Yes, I did it myself, didn't copied it from the internets.
It's optimized per led sub-circuit, not per the whole circuit. Some min-terms do repeat, I am aware.
IMHO it's pretty.