Siebox image headers

Several months ago I found a tutorial on here that explained how to change the sidebox headers to images, and I got it to work. (see www.zingslings.com/shop )

Now I want to go in and use my custom Newsletter header for the newsletter sign up box but cannot for the life of me remember how I changed the others. I've looked through every tutorial on here and checked my english.php file, the specific sidebox php files, tpl_default_box_left, etc. And Nowhere can I find changed I've made.

For example, for my "Shop" header on the left the image is boxhead-categories.gif and I can not find what file that image name is in. I know its uploaded to my includes/templates/custom/images folder but I don't know what file I put the pic name in. I've tried finding it both by using the dev. toolkit in admin as well as searching file after file manually for it.

Can anyone tell me how to find the file that I put this image name in so I know where to start in changing the newsletter signup header? I'm not interested in trying the Image Titles addon or any of that stuff, I know I did it without it the first time but just can't remember how.

Working on something now so the site doesn't look like it should incase anyone is looking right now.

ok I gave up on trying to figure out how I did it before and just used the Image Titles addon.

I think I may have had some similar addon I used before.

It's working now.