would they be willing if you signed a disclaimer?
even if they would im thinking youd be spinning your wheels on trying to repair it. if you were to weld a sleave around the affected area, the welds would only end up a short time later with cracks propagating out of them... chances are if you bolted a sleave around it, im thinking you would only compromise the remaining integrity of the frame. i havnt tried the latter, but i have fabed a sleave for a cancerous frame and welded it up... it worked for about a year <img src="/forums/images/graemlins/frown.gif" alt="" />.