[Trip]

I'm just shooting in the dark here, but you could replace your button images with CSS.
You could add something to your additonal CSS then edit the related templates to call your new CSS to replace those button images. You'll have to adjust/tweak to suit your style.

.buttonadj {
        border-color: #000000;
        border-style:solid;
        border-width:1px;
        padding:2px;
        margin: 2px;
        background: #fefefe;
        font-size: 10px; 
}