More came back. Another NPN with base driven from the BCD "2" input, and the collector tied to the upper segment output, will force it on in all states that include 2. Except for decimal 1 and 4 output, the others have it on anyway, so are don't-cares. When decimal 6 is called for, the BCD 2 will light the upper bar. So, another NPN and base resistor takes care of it.
Ed
