There two great products available at the Home Depot that will work well on Airstreams with a white painted roof.
I noticed that the caulk around the roof vents and sky lights looked like it was put on with a cake spachula. Just horrible workmanship! There were places where lumps of caulk actually acted like a bird bath, holding water up against the edge of the caulk line. Also, with the caulk being about six years old, it was just starting to dry out and crack on the surface.
Here's how I fixed things up quick and easy. The products are called Solar Flex Roof Coating and I also used the caulk that is compatable with this roofing system. I took off the big excess factory blobs the used several tubes of Solar Flex caulk and built an angled bridge away from the roof vents, filled in the factory pockets, and basically smoothed everything out using a 2 1/2 inch putty knife and some slimmy spit. After the caulk had a day to set up, I took a 1 1/2 inch angled paint brush and painted two coats of Solar Flex on all the caulk. Without much skill, the awning rails, vents, sewer stack pipes. and anything else can be coated very easily. It was my preference to wrap the Solar Flex right up the metal sides of the roof vents and sky lights. If you have sky lights, you have probably already heard about the little screws that hold them in place are often drawn down too tight at the factory and crack the plastic vinyl. For one thing, if I was the original installer, I sure would consider using a backer plate or at least a fair size washer under the screw head. Those screws looked like a future leak to me, so I coated the entire sky light except for the surface that obviously needs to remain clear. There's no way a sky light, roof vent, or awning rail can leak if they are maintained this way. Here's the neat part! Once the Solar Flex is dry, it's hardly noticable since it is a white on white application. After a couple days of curing, I took some Glare and polished everything to a like new condition. It works great and there is no reason it shouldn't last for years.
I have also used Solar Flex on an aluminum barn roof about ten years ago. I can tell you this. It absolutely does not peel off and it can take the heat big time. After ten years, when I rub my hand on the surface there is no sign of chalking. This is a fairly thick body acrylic coating that is silky smooth. If I had a major roof leak around a loose rivet or some other mysterious place, I would take about 220 D sand paper, lightly sand the roof down, then coat the entire center roof. (Keep it neat, of course. Consider cutting everything in with two coats first then finishe the application with a roller) The suggestion is to install it during the cool of the morning or on a cloudy day and take the time to put two or three coats on.
Here's the draw back. It only comes in five gallon cans. Perhaps your club could get together and split a can. I used less than two quarts to seal up everything.
The solar flex drys like a rubber swimming pool liner or balloon and stays that way. It bridges gaps and fills in very nicely.