I’m terrible. I saw this message the day you sent it dear anon, said “I will reply to this later” and then promptly forgot.
Ebay is actually a good place to find vintage makeup items (and sometimes where I find some of the pics I use here.. and since I source my images you should be able to trail them back to the sellers who are selling these items.)
There used to be a site that sold a lot of older drugstore items that I visited frequently but it has been so long since I have visited it that I cannot remember what it was and since you brought up purchasing older items it is driving me crazy, I wish I could remember! If I ever stumble across it I’ll be sure to share it here as well.
And sometimes just putting the item you are looking for into a search engine can yield interesting results when it comes to items for sale. Good luck!