The "7" at the beginning of the numbers from the Steve Smith book indicates the length of the shock's stroke, and the second is the damping; since it's only one number (followed by zeroes) that means the fronts are straight 3's and the rears are straight 4's, meaning the damping is the same for both compression and rebound. Your single-digit shocks are that type of shock; the 3-1 means it's a "3" damping (or valving, those terms are interchangeable) and a "1" on rebound. That would be considered an "easy-up" which is good to use on the front when the track is dry-slick to help transfer weight to the rear. A 4-5 has stiffer rebound than compression, also called a "tiedown" (although a 4-5 would be a mild tiedown). That's often used on the left rear to help keep it planted.
I think the four "screw holes" you're referring to are actually spanner holes to take the shock apart for rebuilding.
Here's a couple of links on the Pro Shocks site:
An explanation of their part numbering
http://www.proshocks.com/rshocks/FAQ/FAQ3.htm#faq20
And a setup chart for Mini Sprints
http://www.proshocks.com/rshocks/bas...Base_Minis.htm
If you're still confused (which isn't hard), I'd suggest giving Pro Shocks a call; they could probably help steer you in the right direction; I had all of my shocks dynoed and rebuilt at Advanced and they were very helpful, even to the point of marking each shock with a paint pen to indicate what corner they went on for which track condition. I would expect similar customer service from Pro.