Doug,
Re: your call for assistance on how to attach the top of the straps -
2 methods I can think of other than cut slots:
1) find UK Scout's thread about how he did it. He glued come extra u-bars in near the top and still has the straps coming out of the opening, which is secured with velcro.
2) put a piece of dowel inside just below the top of the opening and epoxy/attatch somehow, into place. Run the strap over this and out of the gap between the JP body and the hole cover.
Either of thses should be secure and easy, and mean you don't have to chop your pack.
Hope this helps a little.
Si