It’s true that stamps have lost their value over the last decades but there are still collectors all over the world. Especially if you don’t know what your looking at I’d do a little research on the internet to learn how stamps are ID’d (you can start with Wikipedia searches of definitive stamps, perforations, watermarks, grills, markings and cancellations, and how stamps are valued and what conditions devalue a stamp). I think you can download a Scott’s stamp catalog from the internet if you don’t want to make a trip to the library. Postage was only 3c from 1863-1883, 2c from 1883- WWI, so lower denominations are more common and worth less but if you have higher denominations you may have some value. I think all but maybe one of the stamps you showed are pre-WWI. Hope you have good luck.
Regarding your comment about stamps having lost value over the decades – I think it depends on the stamps you're talking about. Sure, there was a big boom for stamps during the 1980s, yet those most of those modern issues can be picked up readily for cheap these days. However, there are still big bucks and finds out there. It all comes down to supply and demand, as well as condition or rarity too.
I recently went to a collectables fair, and there were a couple of folks in their twenties and one young ten year old with his grandfather keenly flicking through albums and picking up items on their wants list. Nice to see!
sprailroad: have you since posted up your stamp finds around here somewhere? We'd love to see them!