I also decided to make my own dual-hose clamp for Rubber fuel line out of two bits of steel tubing I had kicking around.
One piece was just a random steel bushing I had that had an ID of 5/8", and then I used the smallest steel tubing I had for the center piece. I welded them together as shown, then cut it in half to allow tubing to clamped in.
Then I cut it off the long center tube (I left it attached for ease of handling) , flattened the cut surfaces on a disc sander, and filed down the welds to create a more pleasing transition. I primed and painted it and I can easily install this onto a frame, a crossmember, or mount it at the end of a bracket. This will hold the fuel and return lines coming from the tank to the Corvette-style Filter/regular mounted on the frame beneath the bed.