Found Addresses, Unknown Addresses

I went into one of the many wonderful stores of Kensington Market the other day. This one had heaps of old postcards, and the nerd that I am, I had to buy some. Most people would buy blank postcards, for future use. I bought postcards already filled in. The oldest from 1911, and a couple from overseas--just for the AIRMAIL stickers.
On these postcards there are still mailing addresses. Do these places still exist? Do the families still live there? I want to write to them, ask them, but is that an invasion of privacy? I'm still undecided.

As for the sender of all the little notes, and the wonderful Christmas card: I forgot I didn't have your address--I got all ready to write you back, let you know what my current playlist is... and realised I don't have your name, let alone your address. But that's fine. I will keep reading your letters for as long as you continue to write to me, and if ever you want some mail back, just pop on your return address. What I really need to do, is buy more blank CDs. Not just for those who write to me, and want to share some tastes in music, but I also have some mixed CDs promised for friends... I always forget when I leave the house, though...

Also, as soon as I have the chance, I am going to scan some letters--not names or personal stuff, but a sample of the hand writing, and all of the drawings.