Posted By:
RobertSThis eBay lot I just noticed should help put this frequently recurring issue to rest. If this is genuine (and it looks likely that it is), this scrapbook indicates square corner cards were around in the 1940s.
Then again, this is all depends on the trustworthiness of the seller...thoughts?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=44821&item=5210040745&rd=1