In my preveous post I forgot to say......
Then cut a piece of wire or plastic rod about 3/16 of an inch long and insert it into the preveously drilled hole's. (thus making a pin on the back of the part.)
Make sure the wire or plastic rod is the same diamiter as the hole.
Leave it to me to give half an answer..... and leave you high and dry...... forcing you to scratchbuild the other half.