I'm not saying it doesn't look bad. It's just, you didn't do anything. It may have taken you an hour to figure THAT BUTTON out. But you didn't do anything. I literally did that in 5 seconds and I don't know anything about GIMP. Airslide tried to help me with making black invisible by going to the ADVANCED button and do some things from there.... and I still can't find the advanced button.
I do have to say, your "retexture" does look a bit smoother. So you may have done a few other things. Probably just the blur tool though.
Remember~ I'm not saying it's bad or anything. Since you are new to GIMP that is definitely explainable. I actually had a post JUST like this. Except it was for a character. And I orange gradient mapped him. He may have looked COMPLETELY different but I didn't do much. I did work on it for an hour or so, but is was just to figure the filters out.
Don't take it the wrong way.
I don't feel like looking for my link, but I'll give you basics. I retextured a character with the sobel and gradient map tool. He turned out SOOOO different. And I thought it looked cool so I posted it. Locrian got on to me about how I didn't do anything it was just a simple filter effect. I got sorta mad but then realized he was right. It was a simple effect.
[EDIT] I decided to look it up anyway. here is the link I spoke of
http://forum.thegamecreators.com/?m=forum_view&t=95117&b=24
Tiggle Bitties