Attended the Orlando Hamfest yesterday, and checked out the class A antennas! Should have taken photos. Most verticles and screwdriver antennas I saw were mounted on the rear ladders, but some were on poles up front. I had an idea to use a creation similar to the Tarheel servo motor (theirs is about $500). For better mechanical support, I would use a wide aluminum plate mounted on top of the roof with the channel bolted on top of the plating. Also saw an interesting telescoping channel system, mounted on the rear end next to the ladder. With the screwdriver mounted on the inner channel, it slid vertically upwards then locked into place.
Deen, W4ANR
Fulltimer Class A
Palmdale, FL