Kathleen,
Did you find the people you mentioned? If you didn't and if you haven't already firgured this out - Create a Free Space Profile...
Upper right of the page are the MENUS > Click ADD > Click NEW THING and add all the information from the card into the form fields. Make sure you put the names in the surname list. Add the info from that card. Add a picture or scan of the card as well.
Post notes in the comments section of profiles on WikiTree that you think might be connected to the post card, about the post card, and link to the Free Space profile you created
IF you have already figured this out, I am happy about that!
Mags