In its original form, a small 45x33x6.5 mm plate, which is screwed to the center bottom of the monorail of the Plaubel PL69, bears two threads for standard 1/4 and 3/8 inch tripod screws. This reduces the contact surface between the camera and the tripod head to the 15 cm**2 of the plate.
When I bought the first Peco Junior, it came with a large tripod with a 3-way Manfrotto head with hexagonal quick-release-plate. As I had equipped a lighter Berlebach wood tripod that I inherited with a Manfrotto ball head, I decided to make the hexagonal plate my standard. Instead of screwing a plate to the Peco Junior, I used a ca. 80x80x15 mm aluminum block to mill a release plate, which could permanently be screwed to the base of the monorail with four M4 screws and corresponding threads in the rail. This increases the camera height and weight a little, but allows by far a much more stable connection between tripod and camera, particularly moving the eigenfrequencies of the connection to much higher values; and the release-plate would have to be carried with the equipment anyway.
