Yeah, I'm hoping they will know what was used or recommend something. I don't mind using Dicor lap sealant, but a brush on product would be OK as well.
I used Kool Seal about 30 years ago on an aluminum roof cabover. Looking on the internet folks say the current Kool Seal is thinner. I may end up using something similar, then when the weather cools here maybe putting eternabond over that. It needs something pretty soon.
I'll see if Bigfoot responds or anyone here has definite answer. If not, I have a trusted RV parts shop I'll be visiting soon.