No line wasn't drawn there. Where I drew the line it never would have gone into a hole. Basically it needed a semi circular drill about 25mm (1 inch) across going down between 10 and 11mm (less than 1/2 inch) in the front 1/3 rd of the heat riser. I should have ground it myself but I didn't back myself to do a neat job. Thanks for the replies and suggestions I will find someone to do it. I think I will patch it. The car was never going to be a show car but it still should have been a neat daily driver.