I have a '98 Klein Mantra comp MTB; the derailleur hanger is bent, stripped and cracked at the bottom. Rest of the dropout, though, is straight. LBS said it could not be repaired because of the crack but offered to sell me a New Old Stock Mantra frame.

Before dropping that kind of change, does anyone have a thought to whether I could either a) straighten the hanger and use a derailleur saver insert or b) cut off the old hanger and file/mill/shape the end for a replaceable hanger? If b) can anyone suggest a suitable hanger (big selection here)?

At one time, Klein frames were guaranteed for life. Does Trek still honor this?

Advice desperately sought.