I read 3 approaches suggested:
1) part number
This is easy on e.g. Google, I see no need for you to do that
2) within a manufacturer.
For that, anyone can go to the manufacturers website.
3) features
Here is a real need, I have often needed a specific '51 derivative (you state '52, I hope you will include the '51s) and, as you described, spent "days" hunting.
I find the way e.g Maxim let you find interface chips extremely useful, if you could come up with something like that it would be my hunting ground.
Using that premise, reducing the search by general features would allow 'special feaures' not to be searchable since the list when condensed by general features could be read in a reasonable time.

Appreciate your efforts, have fun

Erik