Morning Paul,
As your Bailey is only two years old and all the warranties are still valid please see your dealer asap .
I also suggest you email Kelly Watts at Bailey. She is very helpful and may have some ideas,
Isuspect these are glue marks . I guess they do they rub off easily hence the post. IMO if it was damp , mildew would form and that does wash off. Best leave it as it is until the dealer has seen it.