A month ago when I took my '74 450sl (8 cylinder - 4 spd standard shift) in for oil change the mechanic said that he heard the timing belt rattle when he started the car. He estimated it would cost $700 to $800 to fix it now or if I let it break on it's own it would be upwards of $6k as it would involve much damage.

The previous owner (a friend) thinks even if it does break it would not do more harm than needing fixed.

I don't hear any rattle on starting and my s/o agrees the car sounds just like always on starting. The car runs great in my estimation.

Is this mechanic trying to scam me? He did charge me $125 to put an $8 part (took 10 minutes) on my tailpipe previous to this visit.

How does one find an honest mechanic?

Thanks in advance for any advice and thoughts.