Existing mount with Touratech cradle:
DSLR camera rigs use clamps for 15mm rod diameters. These clams are cheap and offer 1/4x20 threaded sockets that a RAM ball can be mounted in. New 15mm rod from McMaster.com machined to match Enduro Engineering's stock rod:
DSLR clamp hardware parts were powder coated black to help prevent corrosion.
New crossbar in place with clamps and RAM mount: