A little off topic, but have you checked out the Xtal Set Society? If
you're going to get into crystal sets (a great idea!) then you'll
probably want to check out they're newsletter and site. Their part's
aren't the cheapest, and I would suggest the other suppliers mentioned
in the thread, but the source of information is great.

As for the Quaker Oat containers, do you have to have Quaker? I've
found many generic brands in my area (great for my use since they are
cheaper, and I don't eat that much oatmeal, but do use them for xtal
set ideas from time to time) that still use the older style container.
Try your local "dollar" stores and such.

Good luck with the project!
Jeramy