My 1989 300SE leaks oil from both top & bottom gaskets, needs motor mounts, and at this point a few other things I haven't discovered yet. My question is, is this a job I can DIY of have a certified mechanic do the job? I have done an engine rebuild, but that was 25 years ago. Still handy, but time is my issue. Car is in good shape but off the road since it also would die on me while driving at 40 mph. Don't know if that was vapor lock or what, but the engine needs to be cleaned up! If it's a mechanic job, what do you think a ball park estimate for a re-build would be?