Kerry, I'll go out on a limb here and suggest that you invest the ten bucks it'll cost to get a copy of the SCTA rulebook - and have it sent directly to the shop that'll be building the cage for you. And I'll go further and suggest that you get written confirmation, right on the purchase order (and be sure to make one so you've got records), that if it does not meet LSR/SCTA specs that they'll bear the cost of redoing/changing, not you. Kind of an "I told you so" proposition from you to them. Specify that they HAVE to do it right the first time.
I get kinda shaky when I hear about shops that haven't ever built a LSR-okay cage - building cages for our kind of racing. A rulebook in the hand might be even more respected by the shop than a photocopy of it. And that way they could see other information that you might not have included when you were making the copies.
Hey - it's only $10 (well, plus some shipping, I suppose). Get two or three books for that shop - as I say: one for the shop, one for the office, and one for the back of the toilet in the men's room. In the long run you'll be the benefactor.