Smauggie, I didn't know you were doing a CZ exhibit. I am fortunate enough to have received some older Family letters as I had Family in Central America from the turn of the Century through the 1950's and have some great covers from the areas.
I'll scan some up later if you'd like to see them. Here is one that I had already scanned into my Photobucket.The thing I really like about this cover is the note that my Grandmother wrote on the envelope.


I like the nice Ancon & Cristobal Canal Zone strikes