Would it not make your programming a lot easier if you use the second shift register just for digit position and the first shift register just for segment and do away with trying to split the digit position between the two shift registers? In other words, move the three connections of shift register 2 to the right by 1 and move the connection from shift register 1 q7 to shift register 2 q0.
This way on the first shift out send a 1, 2, 4, or 8 for digit position and on the second shift out just send the segment pattern.