I've not used aluminium epoxy before, but all the times that I've epoxied holes before and redrilled them, the epoxy has always been plenty strong enough.
What concerns me is the loose pylon.
A picture of how the pylon sits can be seen here.
http://www.thebeachcats.com/modules...mp;file=index&include=view_album.phpIf the pylon is loose then I'd be quite concerned that the epoxy holding it together has come loose inside. You really don't want a loose pylon inside the hull as it will probably be making a point load somewhere on the hull which could well damage the hull. As regards the pylon height, you may need to fill the existing holes with epoxy and re-drill the holes to suit, as long as the top of the pylon has not been cut, the corner casings should fit into them all the way and that should give you the correct frame height.