I have over the years used similar setups as Bob and also consulted Rik Littlefield. However, in the latest incarnation, I found that the required extension could be achieved by using a small yet sturdy bellows device. This allows a better weight balance of the entire rig.
The set up might have been more refined and polished, but it serves the intended purpose well and it is easily removed and something else put there instead if the need arises.