I think the sporran is quite interesting, and I've always wanted to see a hairy cow sporran, as well! The tooling is quite effective, and it's a very good first attempt!

I'd reccomend a couple things for your next one:

Consider making the gusset in a heavier leather, and sew a bead trim around the outside perimeter, where the gusset attaches to the front panel- this will hide the stitches and look quite nice. Use the thinnest leather you can for this purpose and stitch with a dark colored, finer thread.

Also, think about keeping the width of the sporran the same, and making it a bit longer.

For "hair sporrans", the hair usually spans the entire front panel, rather than being framed on three sides by leather. That's another possible design consideration.

As for the loop on the back, I find that the more tightly it fits the sporran belt, the better the sporran hangs. With that in mind, the loop could possibly be a bit shorter and wider. You could, alternatively, use two loops of about the same size as the single one above.

Keep tweaking the design, and make another one as soon as you can (and post pics)! If you have no use for a sporran, I'm sure that you could find a client in one of our fellow board members.