Thinking of replacing ASME propane tank

I have had a 1997 Xplorer 230XL since 2000 and will keep it as long as I can drive. The ASME tank is mounted underneath the passenger side. I scrape and paint it every year or two, but I am worried that it is not enough and it would be good to replace it. I have not found any place that does that. Any ideas? I live just north east of Detroit.