I compared each non-terminal’s expansion to the corresponding slice of the target and inserted exactly the missing integers in the correct order.  All of the newly inserted terminals sum to the 15 missing values.

Updated production rules:
rule_4: A4 -> 1 8 7 6 5 4 3 2
rule_5: A5 -> 30 37 36 35 34 33 32 31
rule_6: A6 -> 38 45 44 43 42 41 40 39
rule_8: A8 -> 46 15 14 13 12 11 10 9
rule_10: A10 -> 47 29 28 27 26 25 24 23
rule_12: A12 -> 48 22 21 20 19 18 17 16