Mouser Electronics is on of the few catalog companies that still sell small
parts one at a time.
They may or may not have your array.
If you have electronic swap meets in your area or surplus outlets, you can
probably pick up an old main board and scavenge for 10-20 bucks.
One last possibility: the reason for the pack is ease of assembly, there is no
technical reason. If there is enough left of the pack to determine
configuration, you can replace the pack with 1/16th watt resistors.
PS: The packs normally use a 3 digit code for value: 1st & 2nd are whole
numbers, the third a multiplier; yours: 5 & 6 & 0=56 ohms.
560 ohms would be 5 & 6 & 1.
Good luck