Originally Posted by
merziac
The outer hole is unusual, the inner is a pretty standard vent hole. The CS seems fine from your pic, I would proceed with caution.
We need an expert opinion, paging
Doug Fattic and
JohnDThompson 
I'm not an expert on chrome but I think the extra hole was for draining chemicals out of the inside after the chroming process. The inside hole was for venting hot air out during brazing. It would be easier to drill a 2nd one for draining then close up the 1st hole so the chroming chemicals wouldn't get in . That is just a guess on my part.