Don't cut the flange part of Van's panel.
Richard,
You need to look again at my photos on pages mentioned in my previous post and what Phil described. We did NOT use the shear on Van's original panel. I used my Dremel scroll saw after drilling holes with the unibit where the rounded inside corners are located. The removed areas of the "frame" from Van's original panel clear all the instruments when the new flat panel is installed. We cut out sections ONLY to keep the outer frame of the original panel intact as a structural member to attach to the three ribs up front, the canopy deck and longeron area, and the upper skin. Notice how I changed my mind about removing part of the original panel on the left side. My parking brake control knob was later installed in that area. The same area on the right side of the original panel got the cabin heat control knob.
You can see in this photo how the frame accepts the sub-panel on the passenger side, and the switch/breaker panels and throttle mounting plates below the bent flange of Van's original panel. The radio stack already has the aluminum angles that stiffen the stack area and attach to the various baskets that hold the transponder and radios that come later. You need to read the August 21, 2004 entry on my PAGE 50 to learn some important details about getting the radio stack mounting angles installed correctly.
http://www.n2prise.org/rv9a050.htm
Here is a view of my scroll saw cutting out a portion of my right sub-panel to accept a CD/Tape player combo unit. I used this same technique on Van's original panel to open up the large areas for instrument clearance of the structural frame that remained. When the cuts are completed, use a good vixen file and Scotchbrite pads to smooth the edges of the cuts from the scroll saw. Use scroll saw blades with the most teeth to get a smooth cut.
The panel sections you make from flat plate aluminum are sheared to make the main instrument sub-panel and the smaller panel for the right side of the radio stack. Both of these are removable. I matched-drilled all the holes in both of my sub-panels to the holes in the original frame from Van's panel. The I enlarged every other hole in the sub panels to clear the screw heads that ALWAYS hold the frame of Van's panel to the structure of the fuselage.
Look at this photo below and you will see what I am talking about. Look at the screw above the ELT test panel. It is one of the screws that secures the instrument panel to the frame of Van's original panel. Now look at the screw above and to the right of the green LED for COM XMIT and you will see the clearance hole in my sub-panel around the screw installed in Van's original panel "frame" that is behind my removable panel. That particular screw is one of three that connect to the three forward top ribs between the instrument panel and the firewall. There is another "clearance hole" around a "frame" screw half hidden behind the upper left corner of my GPS 296.
Looking back at this photo during construction, you can see the "screw clearance holes" better. Those two holes left of the air speed indicator are for headphone and microphone jacks. You should look closely at my PAGE 87 to see how I made some last minute changes to the way the headset and microphone plugs were mounted.
http://www.n2prise.org/rv9a087.htm
Here is one more view of the finished panel showing the screws across the bottom edge of my removable instrument panel. Those screws only hold the sub-panel to the bottom of Van's original panel. Look at the top photo in this post and you will see the bottom curved flange of Van's original panel is still intact. That flange is holding both of my switch/breaker panels as seen at the bottom edge of this photo. They are mounted the same way as the throttle/mixture/prop control panel.
Don't be alarmed about the red LED on the electronic fuel guage. That was an intermittent connection to the capacitive fuel sensors in the right wing tank. It was fixed after getting home from this first LONG cross-country trip after coming out of the paint shop. That photo was taken on the last leg of my first trip to Oshkosh 2005, the Great Lakes area, Ohio, New Jersey, New England, and the return trip to Chattanooga.