Hi Kim,
I have been busy this summer and noticed your request in Button Buddies. Finding a card of plastic cards is very hard to do. A lot of the button collectors removed them from the original cards, so they could place them on "trays". However, many button collections are becoming available and maybe in the bottom of those boxes there might be your treasurer. eBay is your best source for these buttons. However, check the craft area sometimes people who manage to pickup buttons and sell them, don't list them in the collector section.
Are you a members of National Button Society or your local button society? There is an online button group called Button Bytes, but beware about sharing your opinion. The person monitoring the sight will quickly kick you off if she doesn't like it. Many of use have been kicked off because we had an opinion that didn't agree with hers.
May I ask what factory did they work in? Well, hick just email me directly, because I have always been interested in this time period.
Thanks - Linda
Linda Falkenthal