join -t: -o{1,2}.{2,3} inbndtrk1.txt inbndtrk2.txt

##</code><code>##

join -t: -o{1,2}.{2,3} inbndtrk1.txt inbndtrk2.txt \
    | perl -F: -ane'printf "%s %s | %s %s",@F'