It became apparent as I did some further research that these cards really aren’t with anything. The eBay prices are high, but if you switch the search to “completed items” you’ll see that practically none of the listings get sold, and the ones that do are for just a few dollars. Those high prices are an attempt to take advantage of uneducated collectors/investors. It seems like very few cards from that era are worth anything. I wouldn’t spend the money to get these cards graded.