I started out using Medium size, and realized they were much too large for the thickness of leather I was using - Smalls were just right.
The pieces fit together pretty well - you can't quite see the curve of the calf seam in this picture, but it's there:
I did the same thing up the front seam, and then measured and punched the holes for the toe kick. Here's a closeup of the toe kick on the completed gaiter:
You can see the end of the front seam rivet strip - I tapered the end and used a single rivet to attach the top of the toe kick. At that point, I started attaching the straps that wrap around from the shin to the outside of each leg, and eventually buckle up the side. I used decorative steampunk rivet plates from Tandy that look like they're screwed on - they actually are, but from the back. At the toe, I was going through 3 thicknesses of leather, and had to sub out Chicago screws for the ones included with the rivet plates (fortunately, they're exactly the same diameter and thread pitch!)
Having placed the rivets 1" apart, it made positioning the 1" straps pretty easy. They're 8" long - I tapered them with a belt end punch and then marked and punched the belt holes. I punched holes for the two screws on the back of each plate, and used that to attach the straps. After attaching all of these, I placed the strap that goes under the sole of the boot (ideally, just in front of the heel) and riveted it in place:
At this point, I went to figure out where to attach the strap buckles, and realized that the additional material I'd added to the pattern was bunching, so I cut out a small dart and riveted the leather back together with a small overlap. These pictures didn't come out too well - I'll have to retake and update them.
You can sort of see the cut line here, running just above the trio of rivets (one for the dart, two for a buckle) and then out to the other two that mark the overlap. Here's a frontal view:
Blurry as all heck - it was late when I took these, so my eyes probably were focused... The two rivets at the bottom of the pick are the same as the ones on the right of the previous picture. The buckle strap covers up the third rivet, and you can sort of see how the slit puckers a little at the end. I punched a round hole there to mitigate any stress and keep the slit from expanding further.
Then, I cut out short 4" strips, used an oblong punch to cut a hole for the buckle's tongue, and punched rivet holes in each corner. Making an original and using it as a template was a big time-saver. I put the short strips on each buckle, then buckled them onto the long straps using the third hole on the long straps to get a relatively consistent placement - truly professional looking spats have the buttons or buckles in a straight line, but was going for a more tinkerer/homemade look on this pair, so they're not completely straight. I'll save that for Version 2.0.
Then I started the whole process over on the right gaiter... My spouse has a shot of me wearing the finished product. I'll have to grab it from her for the postscript.