Peace, mercy, and blessings of God be upon you. I have Land Cruiser headers, manifold and downpipe without the last muffler (sold). They were removed and I had them on the roof for 10 years and I just took them down. I don't know about leaks or welding. They were removed from a car before I sold it. The sale is easy, just give the part its due. It is preferable to communicate via WhatsApp as I do not frequent the site much.