[AussieinNC]

Ok...now I get what has you stuck....

I have to assume you are using a hand drill and burs or a drill bit itself to elongate the holes....slow work at best...

Do you have access to a drill press?

Last time I did one of these I predrilled where the center of the new hole would need to be located with a small drill bit then gradually opened up the hole until break thru was achieved, than used a dremel bit and grinding stone to finish it off....took maybe half an hour per hole....

If you dont have a drill press, a machine shop would be your best bet....

Good luck...