I opted to let a local repair center do the job. The shop took the window out and sent it to a standard home type window repair place who will replace the newly sealed window and the will bring it back to the rv shop for re-installation. The estimate was about $250. In this north Texas heat there was enough water in there that it sloshed around while driving.
Unfortunately, this decision was driven by the fact that I had to put the rig in the shop to get the left rear compartment door, the rear lower bumper area and other damage repaired by an overzealous state inspector who failed to notice the large truck parked next to him when he tried to make a right turn and the rear end swung out and tore things up. Repairs are amounting $6700 dollars.