If you're willing to drive a bit, maybe give Burlington Glass (in Vermont) a call. I don't know if they specifically deal with frameless RV windows, but I do know they do a lot of somewhat specialized custom work and also auto glass, and (at least for the windshields I've had to have replaced over the years) have done the work well.
You might also try bringing the RV in to a decent local glass shop and letting them examine the mounting. Maybe they're familiar with the technology, but just not the nomenclature of "frameless window."
