Hi Judas:
Airstream's
1964 full line catalog states in Standard Specifications:
"Corrosion-proof removable screens in all windows (Slip-in storm windows available for winter travel)."
so the solid windows in your '64 Overlander might be factory original optional storm windows. I've never seen any so can't offer identifying construction details, but you might have a nice find there. Or a prior owner's handiwork.
In any event, if you have no need for them please offer them for sale in the Classisifed Ads. Someone up north would problably find them quite useful. To quickly get screens, take your storm windows to a hardware store and have a set of screens made from the templates provided by the storm windows, as it sounds like you have all the patterns.
I can't help you with the plastic drawer bins, but again advertise for them in the Classisifed Ads on this and other web sites. Some do show up on eBay from time to time, but it might take a few years to piece together a full set. In the meantime you might want to buy some bins that are close in size at a local interior storage or closet store. Good luck!