Ron:

Some good ideas in your post.

I too was in the same situation (ruptured fuel - off runway) as you described.  Fortunately, we stayed right side up and the door did open.  Upside down would have been a whole new story.  The L-IV-P does not have an opening rear window for egress.  Something else is needed.

I looked at the knife you recommended (the Buck Tiburon)but dont think that it could do the job in a L-IV. (I am assuming that the only way out of an inverted L-IV is thru the acryllic.)   Way back when, the Air Force equipped their T-33 fleet with a canopy bust-out tool.  Sort of an small heavy inpact tool with a blunt point.  It mounted on the canopy rail in a small metal holder. This device would be ideal in a last resort situation....BUT where to find one?????

Anyone have any ideas??   Bill Hogarty @ 10% (rebuilding)