MacBook idling around 70C -- will reapplying thermal paste help?

Necessary info: my Macbook is the late 2008 unibody model with the 2.4GHz Core2Duo, 4GB of RAM, and a 120GB SSD.

I've been attentively monitoring my Macbook's temperature and I have noticed that it seems to idle around 65-70 C. I mostly just use the computer for internet browsing, word processing, and listening to music off my hard drive--but I have seen the temperature veer toward 80-85 C even with such moderate workload.

It has been somewhat difficult to find threads dedicated to this specific model of Macbook, given the proliferation of questions related to the 2008 MBP model, with all of its attendant issues. But from what I have dredged up, it looks as though the normal idle temperature for these machines should be 10-15 C lower, if not more--most people seem to suggest that their temperature at idle or low load hovers around 50 C.

So, I have become somewhat concerned about my Macbook's normal operating temperature. While the temperature never exceeds the CPU throttling threshold or anything like that, still, it seems to me that operating at such (relatively) high temperatures could limit the lifetime of the hardware (all things considered, it is an 8+ year old machine!).

Note: I have recently cleaned out the fan and heatsink grill. As in, within the past month. I took the fan out of the machine and cleaned it meticulously, and gave the heatsink a fair shake of the ol' canned-air treatment.

Would re-applying thermal paste be a worthy endeavor to lower my idle temperatures to more "standard" levels? I've read that Macbooks from the period often come from the factory with excessive thermal paste, which is bad in and of itself and especially bad as the thermal paste loses efficiency over time.

I'm decently versed in working with thermal paste and CPUs, so it's not the operation that concerns me per se, it just seems to be a rather involved operation (which entails inevitable risks... you never know when the next earthquake is going to hit... !) and I don't want to go through with it if it's not going to be worth my time.

Thanks for any advice or testimonies you can offer!