"Project Car, issue #24"
I grabbed this in Barnes & Noble last weekend--it has a Silver NA on the cover.
They do a step by step on the following:
--Energy suspension bushing kit replacement
--Open diff replacement using RX-7 clutch-style LSD
--Willwood brake upgrade. Extra points here--they show that the NA rear brakes can be upgraded to the larger rotors if you swap with a 1.8 caliper bracket. That means you can use the 1.6 brakes and upgrade to larger rotors. Cool and cheap.
--a whole section on stitch welding your chassis and installing a roll
In all, I like the step-by-step approach. It's real-life back yard wrenching, as they're working on a rusty old car and they sometimes use methods that would not be approved by your local ASE certified mechanic.
Otherwise, if you've got an NA Miata, this is a good magazine resource to store with your stack of Playboys.