DErwin, here are pics of DE Stubby instrument panel, and the cross-over tube for the dual throttles.
The instrument panel pic is older, showing a single throttle control under the center of the panel, and several other items have been added, including a second electronic tach. Now there is a tach for each ignition and dual throttles. Also, a cabin heat knob and EGT selector switch have been added. From left to right in the photo: ignition switches, tach, air speed, altimeter, rate of climb, carb heat, Micro-air radio, choke, oil pressure, oil temp, volts, amps, cht/egt gauge, elt panel, various switches and accessory power supply jack.
In the throttle cross-over pic, there are bolts in the end of the red tube that can pivot in the end brackets. The bolts have been secured to ensure they do not loosen, but can pivot in the end brackets. There is a throttle push/pull connected to each end lever. The left side throttle is a lawn equipment product, connected by a bowden cable, where the knob can be turned to lock it in position. At the right is a simple rod/knob push/pull, but no locking action. In the middle of the red tube is the lever where a bowden cable is connected. The other end of this cable attaches to the carb throttle lever. The carb is a Zenith, which works well. We have observed that the intake tubes will form water/frost in certain conditions, so carb heat is available.