Here are some photos of my installation. The first photo shows the rear of the van. The white box is the cabinet for the hot water heater. The connection to the water tank under the sofa is the brass fitting on the lower right. (There is a male cap on the fitting to keep dust out.) The switch for the pump is in the upper left.
Here is the same view with the hose hooked up. The short hose connects to a piece of PVC which is inserted in the jerry can. The PVC has a valve on the upper end which allows it to be "turned off" to keep dust out; there is a PVC cap on the other end when stowed.
Here is the system ready to pump:
This view looks inside the water heater cabinet. The pump is bolted to the rear wall of the cabinet. Power is fed from a 12v source with the hot lead wired into the toggle switch. The inlet side of the pump is connected, via flexible hose, to the brass fitting visible in the first photo. The outlet of the pump connects to a flexible hose which snakes through the cabinets to the water tank under the sofa.
Here is the connection to the water tank. I removed the SMB-provided cap and replaced it with a 90 degree street elbow fitting. The hose from the pump attached to this elbow.
Although not directly related, here is the jerry can basket after the locking bracket is back in place: