We had a 2004 Coachman Pastiche, a great van but the front windows became delaminated.
I used Bondrite S1220 which is a two part acrylic that mixes in the tube during application. It worked for me but that was because the panels had completely come apart and so it was easy to apply and then clamp together using cheap spring clamps.
You say in your case only one edge has been affected, as this is the case i believe it would be easier to use one of the other acrylic adhesives such as WC102 as it is very thin and will run into the gap easier.
Be warned, in my case, when it had cure