This is what I installed:
https://www.amazon.com/gp/product/B076CLPGD3/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
It was $14.99, but I wanted a bunch of different lengths to see how it worked. I ended up using the ones pictured. I reused both stock springs. If anyone is using springs from a ballpoint pen, I'd caution AGAINST cutting the spring for "length". It's about tension. The stock springs are much stiffer than a pen spring. I'd probably use the whole spring and a longer bolt to accommodate. It's all about keeping the appropriate contact on the die with the heatsink (I'm just guessing here...).
View attachment 850862
Here's idle:
View attachment 850866
Here's under a Handbrake load. The IOH diode barely moves.
View attachment 850867
Took about 45 minutes. Most of the time was spent trying to gently remove the caked-on thermal paste on the northbridge die.
The nice thing is the fans barely move now - even under a 100% utilization. Obviously, I replaced the thermal paste on the CPU as well. For reference, I replaced the CPU about 3 years ago with my 6-core. The thermal paste was still tacky and I had moderately good coverage. The Northbridge thermal paste was 100% dry and brittle after 10 years. So, even if folks don't have spring/rivet issues, they might want to consider a new application of thermal paste if the temperatures are starting to climb.
[doublepost=1564605097][/doublepost]Oh, and thanks for pointing me in the right direction everyone. I just keep putting more and more bandaids on this machine... I had a brief moment of "cool... I might actually get a new machine..." But alas... it keeps on trucking.