Stock Photography III (what's selling?)

Well it's been almost a year since I started selling pictures that I have taken. These are the pictures that have been selling so far.

This was one of the more difficult ones to shoot and to get approved. It took me 3 tries. The biggest problem is that this is an isolation, to take the picture I strung the pistol up "upside down" by fishing line inside my home made whitebox. Once it stopped swaying I was able to take the picture. Color correct it, and remove the background. I then used a layer mask and overlaid a copy of the image in gray scale. I clone brushed out any dust, scratches, and the fishing line. Finally I removed any digital noise. The reason it took 3 tries at approval is that Dreamstime's website has very unclear instructions as to what they are looking for in an isolation. Number of times sold, 1.
The Durango and Silverton train at the station is my most popular download so far. Which is surprising as it was my first upload, and I edited it without having much experience. This one was rather complicated as I took the picture before I even thought about selling stock photography. I had to remove the name of the railroad, some tree limbs, several McDonalds related signs in the background, fix the washed out sky, and cover up some mistakes with steam. The sky was actually taken from another image, and I had to do some fancy cut and paste to the locomotive for reasons I cannot remember. Someday I might get ambitious and remove the guy with the red jacket. Number of times sold, 3.
This one was relatively simple. I had to lighten up the shadows and remove the "Scott" name from the SCBA's. Number of times sold, 1 on Dreamstime, and 1 on Crestock.
Same for this picture. Number of times sold, 1 on Crestock (Dreamstime didn't accept).
This is my second most popular upload, and was also problematic. I had to replace the sky, fill in the areas where the sky and tree meet, and cover up some problem areas with smoke. I also deleted some people and a picnic bench from the left side of the train. Number of times sold, 2.
I did not take this picture but never the less it caused me much pain. Both Crestock and Dreamstime allow you to upload your own x-ray's, so I did. I just remove my information. Number of times sold, 1.
Ah yes the humming bird image. This one was rejected by both Dreamstime and Crestock. Although I was able to fix it enough to get it re-accepted by Dreamstime. I didn't bother with Crestock. Number of times sold, 1.
This one is my personal favorite. The only things I did to it was to remove the word Phoenix from the truck, some power lines, and enhance the color. Number of times sold, 1.
That's it so far. All that hard work has earned me $8.75. Woo hoo!