Hi jwr, I have been considering adding a section with Partsbox.io and Partkeepr but have been hesitating because I don't have any personal experience with them yet. But given I got this review from a redditor I should probably add it: https://www.reddit.com/r/electronics/comments/5oc84d/a_curat...
On a side note I would love to pick your brain sometime about starting a business in this area as I am considering the avenues for turning my project sharing site https://kitnic.it into one.