Roof paint blistering on older Marco Polo

[Dom]

I got my ‘67 plate Marco Polo in 2023. The roof pain was fine at the time. It has since developed some blistering. The local MB dealer has helpfully taken photos and sent them to MB UK. Local dealer was hopeful they would replace roof as low mileage and in good condition. MB UK has said it won’t replace roof as Marco Polo now 9 years old. I’m just wondering if there are any precedents of owners on here having roof blistering problem fixed by MB with an older van. Thanks in advance.