What a nice peek and reminder of a different era. Even if we were alive when some of the photos of our relatives were taken, we don't always have a real perspective of the time- as we were just living it. I've got a trailer that's quite a bit older than I am, and I'm always trying to imagine what it would have been like during that time period. Probably to the annoyance of some of my friends and family, I will ask about things from that time.
I think it's so great that you have a family connection to Airstreaming. I have a connection to camping, both tent and rv, in my family, as well as boating, so it's in the blood! But what fun to have albums and journals of their experiences!
previously, you mentioned the badges. They could be displayed in frames, perhaps, maybe shadowboxed with copied photos of your grandparents (with archival ink and UV protective glass). You could have a virtual memory box on the wall, so they can always travel with you in your Airstream!!