We have been trying to find the comic, but it seems that it's going to be a tough task. It's not a popular comic, so there aren't many copies of it, being a late 50's publication. We haven't found it in any comic store or websitet (scanned). However, we are not going to give up in our search, and will keep on digging up the internet to find it. We are pretty sure that the Mystery Tales 40 contains important clues for the Lost's plot, so we are going to find them out!
If you know someone that has the comic and would want to share its content with us, please contact us ASAP.