I don't really like the borders and the backgrounds could use some work. The scan lines/grids don't really add anything to the images. The text on the first one is pretty good, but a little too big maybe. I'd make the overall size of the sigs smaller too.
tech borders are shoddy and weak. they lack originality altogether. A 1-3 pixel black border would do them justice after you scale down the size and definitely do something about the scanlines... even if you just lower the opacity of the scanline layer. keep on plugging away though. you are surely on the right track to graphic success.