I bought some op-amps from Aliexpress a few days ago. They seem to be working. I patted myself on the back for getting a such a deal, they were about $0.08 each!
All of the parts seem to be working except fro the LM308 which didn’t work at all.
After watching this video, I’m starting to think that all of them could be fake! Seems like companies are manufacturing op-amps, that work as op-amps, but are marking them with other part numbers.
Here is a link to a discussion on DIYStompboxes.com forum.