Просто для исправления вашего awk:
awk 'NR==FNR { n[$1]=$0;next } ($1 in n) { print n[$1],$2 }' file1 file2
#Output:
0000abc5abc3 GR096 GR097
0000def5ae87 GR001 GR001
0000cab5aea3 GR001 GR001
0000bac5aeeb GR001 GR001
0000fed5af13 GR001 GR123
0000cba5b187 GR001 GR169