How to filet a Ventura 69.
Continued drilling with Dremel (actually, 'Sears Rotary Tool') until 4 screw shafts pushed thru (2 on each side (L,R) of film gate.
The whole film gate is formed with 'dimples' and bent so that it tightly snaps over the bellows. I took a 1/4" x 1" piece of steel and pried gently up on the L & R sides where the screws were removed and the bottom side came out, revealing the formed shape. A little more pressure on the sides closer to the top and the top rail lifted out. The top and bottom are tightly snapped between the other body shell layers. I thought it was one piece until I got it apart.
The whole gate and roller ass'y lifted out apparently unharmed revealing 4 folded over bellows flaps, barely glued down. I was able to pry bellows loose with fingernails.
I switched from the spherical cutting tool which was hard to steer and removed material very slowly to a cylindrical coarser looking cutting tool. The folding arm pivots were anchored mid-body, top & bottom with large head nickeled brass pins. Ground those off and the 4 rivets holding the folding hinge and it all came apart leaving the back. Cut-off wheel removed the shutter release button.
Free and clear now.