lol, dont be embarased. I did that cos i could see some white staining in the green circle, thought maybe it was cracked.

OK, that should have a very tiny core plug in it, i duno if you will find one that small of if its even worth doing, you can just as easily put a new housing on, 3 x 10mm bolts. However you do run the risk of them snapping which they like to do.....